Answer:
More damage is done and more life is endangered in a head-on collision of two cars, each traveling at 30 mph, than in a car crashing into a brick wall at 30 mph because the relative velocities of the head-on collision are the sum of the two velocities.
Explanation:
Car crashing to a brick wall at 30 mph is less dangerous than two cars travelling in opposite direction at 30 mph each.
This is because, for one car, the other is at a relative speed of 30+30 = 60 mph.
The built in flash in a compact camera is usally capable of giving correct exsposure for distance up to how many meters?
Answer:
An on-camera flash is an indispensible accessory for many photographers; it provides additional light when conditions become too dark to handhold your camera comfortably, allows you to achieve more balanced exposures in daylight conditions, permits freezing of fast-moving subjects and can also be used to control or trigger other flash light sources. Additionally, a flash can be used as a highly effective creative tool to establish an aesthetic that elevates your imagery when lighting conditions are considered less than stellar. The benefits of an external on-camera flash far outweigh those provided by a built-in camera flash, while the only drawback is keeping an additional piece of equipment.
On-Camera Flash versus Off-Camera Flash versus In-Camera Flash
The term on-camera flash simply refers to a type of strobe light (flash) that can connect directly with your camera. While it is referred to as “on-camera” this does not require the flash to be physically mounted on your camera. On-camera flashes can, and often are, used off-camera. This differs from other strobe-light sources, such as studio pack strobes and monolights in that these types of strobes are not meant to be physically connected to your camera (except under rare and unusual circumstances involving convoluted methods of adaptation). Additionally, on-camera flashes usually have a self-contained power supply, although external power sources can sometimes be used to improve performance or battery life.
On-camera external flash also refers to the type of external flash that can be used on your camera, compared to a built-in flash that is integrated into many cameras. An on-camera external flash performs better than a built-in flash in almost every regard with the one exception that it is not built into your camera. The ability to take the flash off your camera results in a significantly greater number of lighting options; far more than simply providing a blast of flat light to the scene to facilitate an adequate exposure. It is often not desirable to have your flash pointed squarely at the scene at hand; more often than not you will want to bounce the flash light off other surfaces and point in other directions to control the look of your flash. When using an in-camera flash, you are forced to use the flash at the given angle from which it extends.
Most built-in flashes are also located near the camera lens, which can often result in the red-eye effect when photographing subjects in dimly lit conditions. Red-eye occurs because pupils dilate in dim light, the built-in flash is aligned with the lens's optical axis, its beam enters the eye and reflects back at the camera from the retina at the rear of the eye, which is quite red. Being able to use an on-camera flash source off-camera, from a different angle, will help to eliminate the red-eye effect in your photographs of people.
Guide Numbers, Manual Usage, Controlling Flash Power and Sync Speeds
Before delving into the automatic technology that is contained within most contemporary flashes, it is best to understand how to manually control and grasp a flash’s power. This is directly related to having an understanding of exposure ratios—how shutter speeds and apertures affect and balance each other—even though auto-exposure metering is available and often utilized for determining the best exposure settings.
Explanation:
A 70kg skier moving at 5 m/sec down a slope what is the skier’s momentum
Answer:
Momentum of the skier is 350 Kg.m/sec
Explanation:
Momentum of a body can be calculated using the following rule:
P = m * v
where:
P is the momentum of the body
m is the mass of the body given as 70 Kg
v is the velocity of the body given as 5 m/sec
Substitute with the givens in the above rule to get the momentum of the skier as follows:
P = m * v
P = 70 * 5
P = 350 Kg.m/sec
Hope this helps :)
How much heat is released to freeze 47.30 grams of copper at its freezing point of 1,085°C? The latent heat of fusion of copper is 205.0 J/g.
Answer:
=9696.5J
Explanation:
The latent heat of fusion of a unit mass of copper is the heat released when it changes from its molten state to solid state of the heat absorbed to melt it.
The total energy released is calculated using MLf where M is the mass of the copper and Lf is the latent heat of fusion.
=mLf
=47.30 grams×205.0J/g
=9696.5J
Answer:
-9697
Explanation:
thats the answer
state the following: Boyle's law and Charle's law
Boyle's law states that the volume of a given mass of gas is inversely proportional to the pressure provided that the temperature remains constant.
Charle's law states that the volume of a given mass of gas is directly proportional to temperature provided that the pressur remains constant.
Boyle's Law is a law stating that the pressure of a given mass of an ideal gas is inversely proportional to its volume at a constant temperature
find the average speed of a car that goes 80 miles in 3 hours.
Answer:
average speed = 80/3 miles per hour (exactly)
average speed = 26.7 mph (approximately)
Explanation:
average speed = distance/time
average speed = (80 miles)/(3 hours)
average speed = 80/3 miles per hour (exactly)
average speed = 26.7 mph (approximately)
Explanation:
80/3 mph is the average speed
To move a heavy object, like a refrigerator what could be used to help decrease the frictional force?
Pick all that apply.
A. Remove everything in the refrigerator to lighten the load.
B. Put a lubricant between the surface of the object and the floor
C. Use round objects, like pencils , to decrease the friction and push the refrigerator over the pencils more easily
D. Use more force to push the refrigerator, with the help of a friend
(APEX)
Answer:
A. Remove everything in the refrigerator to lighten the load.
B. Put a lubricant between the surface of the object and the floor
C. Use round objects, like pencils , to decrease the friction and push the refrigerator over the pencils more easily
Explanation:
Force of friction is a resistance force which acts between two surfaces which are in relative motion. Friction is both boon and bane. Due to friction, we are able to sit, walk etc but also, due to friction there is dissipation of energy. Friction can be reduced by applying lubricants, reducing contact area, reducing the load.
F = μN where N is the normal force which depends on the mass.
Thus, by reducing the load, force of friction can be reduced. Round objects like wheels can also be used. By this the contact area reduces.
Question 1 of 20 :
Select the best answer for the question.
1. Which objects are scattered
throughout the galactic halo that
surrounds the Milky Way?
O A. Superclusters
O B. Globular clusters
O C. Black holes
O D. Magellanic clouds
Answer:
B. Globular clusters
are scattered throughout the galactic halo that surrounds the Milky Way.
Explanation:
Which muscles are voluntary?
a. skeletal and cardiac
b. smooth and cardiac
c. smooth only
d. skeletal only
Answer: skeletal only
Explanation: Cardiac muscle (also called heart muscle or myocardium) is one of three types of vertebrate muscles, with the other two being skeletal and smooth muscles. It is an involuntary, striated muscle that constitutes the main tissue of the walls of the heart.
Smooth muscle is responsible for muscle tissue in which the contractile fibrils are not highly ordered, occurring in the gut and other internal organs and not under voluntary control.
Hope this helps
PLEASE ANSWER FIRST GETS BRAINLIEST
If you place a compass near an electrical current, explain what should happen and why
Due to electric current a magnetic field is generated. So when a compass is placed next to an electric field, it shows deviations.
The compass shows the direction of the North. Therefore the direction of the magnetic field can be found. This is found using the right hand rule.
The SI unit that is used to measure time is the
Answer:second
Explanation:
Answer:
The SI unit that is used to measure time is the 'second'.
Explanation:
The International System of Units has defined seven units of measure which are considered as a basic set from which all other SI units can be derived.
Hence, the base unit defined to measure the time is second. It is defined by the oscillations of the radiation which correspond to the transition between two levels of the caesium atom.
If this plastic cup is heated to its melting
point, what will eventually happen to all
the particles in the plastic?
A. The particles will begin to move enough
that they slide past each other.
B. Bonds will form and the liquid will become
a solid.
C. The spaces between the particles will get
smaller.
D. The particles will change state and become
a crystalline solid.
Answer:
A. The particles will begin to move enough
that they slide past each other.
Explanation:
When the plastic cup is heated, the Kinetic energy of its particles starts increasing. As the temperature rises, the kinetic energy keeps increasing. With the increase of K.E, the particles start moving faster and faster. When the temperature finally reaches the melting point, the K.E of the molecules is enough to break the bonds and slide past each other.
a satellite is orbiting Earth at a distance of 35 kilometers. The satellite has a mass of 500 kilograms. what is the force between the planet and the satellite
Answer:
The force between the planet and the satellite is 4.76 * 10³ Newtons
Explanation:
Given:
Mass of satellite = m = 500 kg
Distance of the satellite from Earth's surface = h = 35000 m
We know that:
Mass of Earth = M = 5.9 * 10²⁴ kg
Radius of Earth = R = 6.4 * 10⁶ m
Gravitational Constant = G = 6.673 x 10⁻¹¹ N m²/kg²
Force between Earth and an object is given as:
F = GmM/(R+h)²
= (6.673 x 10⁻¹¹ x 500 x 5.9 x 10²⁴)/((6.4 * 10⁶)+(3.5*10⁴))²
= (1.97*10¹⁷)/(6.435*10⁶)²
= (1.97*10¹⁷)/(4.14*10¹³)
= 4.76 * 10³ N
Answer: F = 4.76 * 10³ N
Explanation:
We know that the force of gravity between two objects is:
F = G*m*M/r²
Where M is the mass of earth, m is the mass of the satelite, r is the distance between the radius of the earth and the satelite and G is the gravitational constant, and the data that we have is:
Mass of satellite: m = 500 kg
Distance of the satellite from Earth's surface: H = 0.035x10^6 m
Radius of Earth: R = 6.4 x 10⁶ m
So we have that r = R + H = 6.435x10^6
Mass of Earth: M = 5.9 * 10²⁴ kg
Gravitational Constant: G = 6.673 x 10⁻¹¹ N m²/kg²
Then the force that the Earth does in the satellite is:
F = (1.97*10¹⁷)/(6.435*10⁶)²
F = (1.97*10¹⁷)/(4.14*10¹³)
F = 4.76 * 10³ N
What are close-toed shoes least likely to provide protection against?
hydrogen gas produced during a reaction
spilled water from a hot-water bath
broken glass from a dropped test tube
acid leaking from a cracked beaker
Answer: Hydrogen gas produced during a reaction
Explanation:
A chemical lab is a place where potential hazards oriented to the use of the chemicals can happen. These chemicals can cause injuries to the skin when come in contact directly or indirectly. Therefore, protective safety measures should be taken so as to protect oneself while working in a chemical lab.
Among the options given, hydrogen gas produced during a reaction is the correct option. This is because of the fact that close-toed shoes can provide protection against all types of chemical fluids. But the gases like hydrogen gas are reactive and they are permeable inside the shoe material hence, may cause damage.
please answer quick
The man is sitting on a bench. His mass exerts a force of 720 newtons down against the bench. What force does the bench exert against the man?
A. 0 N up
B. 360 N up
C. 720 N up
D. 1440 N up
Answer:
C. 720 N up
Explanation:
Newton's third law states that:
"When an object A exerts a force on an object B, then object B exerts an equal and opposite force on object A"
In this situation, we can imagine the man to be object A and the bench as object B. The force exerted by the man on the bench is:
720 N, down
So according to Newton's third law, the bench must exert an equal and opposite force on the man. Therefore, the force exerted by the bench must be
720 N, up
an aluminum bar is 2 m long at temperature of 20 degrees C what was the length of the bar be at temperature hundred degrees Celsius
Answer:
L=2.003696
Explanation:
The question is on expansion due to heat
The general formulae is;
L= L₀ { 1+∝(T₂-T₁)}
where L₀ is initial length of bar at 20°, L is length of bar at asked temperatures, ∝ = 23.1× 10^-6 °c , T₂ is the final temperature, T₁ is the initial temperature in °c
Given;
L₀=2m
T₂=100°c
T₁=20°c
∝ = 23.1× 10^-6 °c
Substitute values in the equation
L= L₀ { 1+∝(T₂-T₁)}
L=2{1+23.1× 10^-6(100-20)}
L=2{1.001848}
L=2.003696
Final answer:
The length of the aluminum bar at a temperature of 100 degrees Celsius would be approximately 2.0009 meters.
Explanation:
The length of a metal bar can change with temperature due to thermal expansion. The relationship between the change in length and the change in temperature is described by the thermal expansion coefficient of the metal. In this case, we are given an aluminum bar that is 2 m long at a temperature of 20 degrees Celsius. To find the length of the bar at a temperature of 100 degrees Celsius, we can use the formula:
Lfinal = Linitial * (1 + α * ΔT)
Where Lfinal is the final length, Linitial is the initial length, α is the thermal expansion coefficient, and ΔT is the change in temperature. The thermal expansion coefficient for aluminum is approximately 0.0000225 per degree Celsius. Plugging in the given values:
Lfinal = 2 * (1 + 0.0000225 * (100 - 20))
Lfinal ≈ 2.0009 mSPJ11
Positively charged particles within the nucleus of an atom are _________. A. electrons B. protons C. neutrons
In fact, all particles (atoms and molecules) in nature contain an equal number of protons (plus charged basic particles) and electrons (minus charged basic particles). Therefore, it is natural that the particles are uncharged.
The positively charged particles within the nucleus of an atom are protons. So, the correct option is B. Protons. Protons carry a positive charge while neutrons within the nucleus are neutral.
The positively charged particles within the nucleus of an atom are protons. Protons carry a positive charge that is exactly equal in magnitude to the negative charge carried by electrons. In a neutral atom, the number of protons in the nucleus is balanced by the same number of electrons outside the nucleus. It is important to note that neutrons, which are also located in the nucleus, carry no charge (they are neutral).
To summarize the particles in the nucleus:
Protons: Positively charged
Neutrons: Neutral (no charge)
How much elastic potential energy is stored in a bungee cord with a spring constant of 10.0 N/m when the cord is stretched 2.00 m?
A. 10.0 J
B. 20.0 J
C. 40.0 J
D. 200 J
Elastic potential energy stored in bungee cord is 20.0 J.
Answer: Option B
Explanation:
The elastic potential energy is a form of potential energy stored in elastic materials. Generally potential energy is the energy of any object when it is at rest. But in materials possessing elastic properties, they store these potential energy in the form of elastic potential energy and it is used when the elastic materials undergoes elastic deformation.
For example, if we consider a spring, the elastic potential energy of the spring will be zero, when it is not deformed elastically i.e., when the spring is not stretched or compressed. But the same spring will be exhibiting elastic potential energy when the spring is stretched or compressed. So, the formula for elastic potential energy is
[tex]\text { Elastic potential energy }=\frac{1}{2} \times \text { spring constant } \times\left(\frac{\text {stretching}}{\text {compressing distance}}\right)^{2}[/tex]
In this case, as the spring constant of cord is given as 10 N/m and the stretching distance of the cord is given as 2 m, so the elastic potential energy stored in the cord will be
[tex]\text { Elastic potential energy }=\frac{1}{2} \times 10 \times(2)^{2}=\frac{1}{2} \times 10 \times 4 = 20 J[/tex]
A good way to de-magnetize something is to___.
A.) run a current through it.
B.) put it near a compass.
C.) heat it.
D.) place it in an electric field.
Answer:
C.) heat it.
Explanation:
The best method to de-magnetize something is to heat it up to its Curie temperature. This disrupts the magnetic field, making the material lose its magnetic properties.
Explanation:The means to de-magnetize an object differ based on the nature of the item, but generally, one effective way to de-magnetize something involves heating it, option C.) Therefore, you can remove or disrupt the magnetic properties of a object by increasing its temperature. When an item is heated to a particular point, known as the Curie temperature, its magnetic domains become disorganized and the material is no longer magnetic. Other methods may involve disrupting the magnetic field via other means, but heating is a straightforward and commonly used method.
Learn more about De-magnetization here:https://brainly.com/question/20226052
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Rita conducts an experiment on how the amount of precipitation each fall affects
the number of grasshoppers each spring. How should Rita organize her data?
Answer:
Explanation:
As spring season is a yearly phenomenon so, Rita should organize her data on yearly basis. Firstly, she should plan the procedure of her experiment and collect the data according to it. Secondly, identify the attribute of each object of her experiment. Thirdly, she can organize and segregate her data in tabular form, graphical form or diagrammatically.
Need help ASAP ????????
Answer:
Question 1 is true, question 2 is b
Which statement is true for light passing into a medium that is more optically dense than the first medium through which it past
Answer:
light is refracted towards the normal.
Explanation:
The more dense medium have a higher refractive index and so the light slows down towards the normal.
The answer is the index of refraction of the second medium is lower.
3. Which is not a primary color of light? blue red green yellow
Answer:
GREEN
Explanation:
Red, Blue, And Yellow are the only Primary colors.
No 2 colors can be combined to make Red, Blue, or Yellow, BUT BLUE AND YELLOW CAN BE COMBINED TO MAKE GREEN.
Therefor, Green is NOT a primary color of light!
Yellow is not a primary color of light.
Hence, the correct option is D.
In the additive color model, which is used in displays like computer screens and TVs, the primary colors of light are red, green, and blue. When combined at full intensity, these colors produce white light.
On the other hand, in the subtractive color model, which is used in mixing pigments like paint or ink, the primary colors are magenta, yellow, and cyan. When mixed in equal amounts, these colors produce black.
While blue, red, and green are primary colors of light, yellow is a primary color in the subtractive color model, but not in the additive color model of light.
Therefore, Yellow is not a primary color of light.
Hence, the correct option is D.
To know more about primary color here
https://brainly.com/question/29117588
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why does a person while firing a bullethold the gun tightly to his shoulders?
Answer:
in order to celebrate the animals victory!
Explanation:
because they have spent a long time in this revolution. they finally won so theyre firing bullets for celebration
choose the more reactive nonmetal. P or O
Oxygen (O) is generally considered the more reactive nonmetal compared to phosphorus (P), due to its higher electronegativity and its strong oxidizing properties.
When comparing the reactivity of phosphorus (P) and oxygen (O), it is important to consider their positions on the periodic table and their chemical properties. Oxygen, which is in the chalcogen group (Group 16), is a highly reactive nonmetal and a strong oxidizing agent that forms compounds with most elements. Being more electronegative, oxygen has a greater tendency to attract electrons, which makes it more reactive than phosphorus in many situations.
Phosphorus is also a very reactive nonmetal, particularly in its white phosphorus form, which can spontaneously inflame in air. However, in reactions with other nonmetals or in the formation of oxides, oxygen's higher electronegativity usually makes it the more reactive element. Therefore, oxygen is considered to be the more reactive nonmetal when compared to phosphorus.
the momentum of a car travelinv in a straight line at 20 m/s is 24,500kg·m/s. what is the cars mass?
Answer:
Explanation:
V= 20m/s
M= 24,500kg.m/s
M = m x v
m = M/v
m = 24,500/20
m = 1,225kg
A force of 4400 N is exerted on a piston that has an area of 0.020 m.
What force is exerted on a second piston that has an area of 0.040 m-?
A. 8800
B.220,000
C.88
D.2200
Use Pascal's Law.
F1/A1 = F2/A2
F1 = 4400N
A1 = 0.020m^2
F2 = X
A2 = 0.040m^2
4400/0.020 = X/0.040
Cross multiply:
(4400 * 0.040) = 0.020X
176 = 0.020x
Divide both sides by 0.020
X = 176 / 0.020
X = 8800
The force is 8800 N
use pascal's law..to solve the question
Which of the following should not be included in a great summary?
A. Blaming your lab partner
B. New questions your experiment has generated
C. Your prediction
D. Your investigation plan
What’s the velocity of a ball falling with 100 joules of kinetic energy and a mass of 2 kilograms
Answer:
the velocity is 10 m/s
Explanation:
Using the expression for kinetic energy we have:
[tex]Ek=\frac{1}{2} *m*v^{2} \\\\Ek=100J\\m=2kg\\v=\sqrt{(2*100/2)}\\ v=10[m/s][/tex]
Answer:
10 m
Explanation:
What is the shape of an ammunition molecule
Answer:
The shape is a trigonal pyramidal shape.
Hope this helps you.
state an advantage of using such hydraulic jack to lift a load
Answer:
Explanation:
You are going to lift and press down on the 200 N many times and move only a short distance. The reward is that slowly but surely you will lift a very heavy load -- one that cannot be managed any other way but by the hydraulic jack.