A soccer player kicks a soccer ball of mass 0.45 kg that is initially at rest. the player's foot is in contact with the ball for 1.6 × 10-3 s, and the force of the kick is given by f(t) = [(7.0 × 104)t - (1.6 × 106)t2] n for where it is in seconds. find the magnitudes of the maximum force on the ball from the player's foot during the period of contact,

Final answer:

To find the height from which the ball was thrown, we can use the equations of motion for projectile motion. The ball was thrown from a height of 44.1 meters.

Explanation:

To find the height from which the ball was thrown, we can use the equations of motion for projectile motion. Since the ball is thrown horizontally, the initial vertical velocity is 0. We can use the equation h = (1/2) g t^2, where h is the height, g is the acceleration due to gravity, and t is the total time the ball is in the air.

Using the given values, we can substitute g = 9.8 m/s^2 and t = 3 s into the equation to solve for h: h = (1/2) * 9.8 m/s^2 * (3 s)^2 = 44.1 m.

Therefore, the ball was thrown from a height of 44.1 meters.

Short answer:

So that the cyclist does not slide back down

Long answer:

The main forces a cyclist must conquer are air resistance and gravity. Air resistance increases exponentially with speed. In the switch from cycling on a flat road to hiking a hill, the decreased speed reduces air resistance to the point where drafting other riders offers small benefit. At this point, smaller cyclists, who have finer power-to-weight ratios, will be able to break away from the peloton. Climbing skill can be improved by minimizing weight, and also by pedalling at a constantly elevated rhythm. Large cyclists can attain greater downhill speeds, but on mountainous courses smaller cyclists still have a benefit. 

Answer: 290 J

Explanation:

1) Data:

i) Max's mass = 15 kg

ii) Maya in a sled's mass = 20 kg

iii) slippery snow ⇒ no friction

iv) F = 12 N

v) α = 15°

vi) d = 25 m

2) Physical principles and formula

i) The mechanical workg, W, developed by a constant force, F, that has an angle α with the displacement d, is given by the formula:

W = F × d × cos(α).

ii) The mass of Max is not relevant for the problem, nor the mass of the sled, since the fact that there is not friction, results in that the only force acting is F (12 N, α = 12°).

3) Solution:

W = 12 N × 25m × cos (15°) ≈ 290 J

Work done by Max on the sled is about 290 J.

[tex]\texttt{ }[/tex]

Let's recall the Kinetic Energy and Work formula as follows:

[tex]\boxed {E_k = \frac{1}{2}mv^2 }[/tex]

Ek = kinetic energy ( J )

m = mass of object ( kg )

v = speed of object ( m/s )

[tex]\texttt{ }[/tex]

[tex]\boxed {W = F d}[/tex]

W = work done ( J )

F = force ( N )

d = displacement ( m )

Let us now tackle the problem!

[tex]\texttt{ }[/tex]

Given:

mass of Max = m = 15 kg

mass of Maya and sled = M = 20 kg

magnitude of force = F = 12 N

direction of force = θ = 15°

displacement = d = 25 m

Asked:

work done by Max = W = ?

Solution:

[tex]W = F_x \ d[/tex]

[tex]W = ( F \cos \theta ) d[/tex]

[tex]W = ( 12 \times \cos 15^o ) \times 25[/tex]

[tex]W \approx 290 \texttt{ J}[/tex]

[tex]\texttt{ }[/tex]

Work done by Max on the sled is about 290 J.

[tex]\texttt{ }[/tex]

[tex]\texttt{ }[/tex]

Grade: High School

Subject: Mathematics

Chapter: Energy

The minimum distance the truck can stop in without the box sliding into the cab is equal to 77m.

The equations of motion can represent the relation between the initial and final velocity, acceleration, displacement, and time of a moving object.

The equations of motions are usually represented as shown below:

[tex]v = u +at\\S = ut +\frac{1}{2}at^2\\v^2 -u^2 = 2aS[/tex]

Given, the final velocity of the truck, v = 100 Km/h

The third equation of motion: v²- u² = 2ad

v² - 0 = 2 × a × d

a = v²/2d

The coefficient of static friction between the box and the truck = 0.54

We know that, F = ma = [tex]\mu_{s}m g[/tex]

[tex]a = \mu_{s} g[/tex]

[tex]{\displaystyle \frac{v^2}{2d} = \mu_s g[/tex]

(100)²/2d = 0.54 × 9.8

d = 73 m

Therefore, the minimum distance the truck can stop is equal to 73m.

Learn more about the equation of motion, here:

brainly.com/question/16982759

#SPJ5

To reduce the dissipated power by 10% while maintaining the same leakage current, the voltage needs to be reduced in such a way that the new power dissipation equals 90% of the original power, due to the direct proportionality between power and voltage in the formula P = IV.

The question asks: If the total dissipated power is to be reduced by 10%, how much should the voltage be reduced to maintain the same leakage current? Power dissipation in an electrical circuit is described by the formula P = IV, where P is the power in watts, I is the current in amperes, and V is the voltage in volts.

To find the new voltage required to reduce the power dissipation by 10%, we first have to understand that if the leakage current remains constant, the power reduction is directly proportional to the reduction in voltage. Given the initial power Pm = 1.0 × 10³ W, reducing this power by 10% results in Pnew = 0.9Pm = 0.9 × 1.0 × 10³ W.

Since P = IV and I remains constant, the new power equation after reduction can be written as 0.9Pm = I × Vnew. Substituting the values and assuming the initial current remains unchanged, we solve for Vnew, resulting in a voltage reduction proportionate to the desired 10% power reduction.

a) In this case the forces are the centrifugal force Fcp, which is directed horizontally toward the wall; the force of static friction Ff with the wall, directed upward; the normal force Fn by the wall, which is directed away the wall; the force of gravity Fg, directed downwards. Then we have that the horizontal forces are all equal in magnitude; similarly the vertical forces are also all equal in magnitude.

b) The minimum coefficient s occurs when force of gravity is equals the max friction force, that is

Fg = Ff,max

m g = s Fn

Also, the normal force has equal magnitude to the centrifugal force:

m g = s Fcp

m g = s m w^2 r

g = s w^2 r

s = g / (r w^2)

With values: g = 9.81 m/s^2; r = 2.5 m; and w = 2pi * 0.60 = 3.77 rad/s; we find

s = 9.81 / (2.5 * 3.77^2) = 0.276

The minimum value of coefficient of static friction for which the person does not slide is [tex]\boxed{0.276}[/tex].

Further Explanation:

As the cylinder start to rotate, the people standing against the wall remain stick to the wall. So if we draw the free body diagram of the person, then we can see the balanced forces acting on person's body.

Given:

The rate of rotation of the cylinder is [tex]0.60\text{ rev}/\text{s}[/tex].

The radius of the cylinder is [tex]2.50\text{ m}[/tex].

Concept:

The friction force between the person’s body and the inner surface is balanced by the gravitational firce acting on the person's body.

[tex]\boxed{f_\text{friction}=f_\tect{gravity}}[/tex]                                                   ...... (1)

The force of friction acting on the person's body is:

[tex]f_\text{friction}=\mu N[/tex]

Here, [tex]N[/tex] is the normal reaction,  [tex]\mu[/tex] is coefficient of static friction.

The gravitational force acting on the person's body is:

[tex]f_\text{gravity}=mg[/tex]

Here, [tex]m[/tex] is mass of the body, and [tex]g[/tex] is the acceleration due to gravity.

Substitute [tex]\mu N[/tex] for [tex]f_\text{friction}[/tex] and [tex]mg[/tex] for [tex]f_\text{gravity}[/tex] in equation (1).

[tex]{\begin{aligned}\mu N&=mg\\\mu&=\dfrac{mg}{N}\end{aligned}[/tex]

The Normal force acting on the person's body is balanced by the centrifugal force acting on the persion due to the rotation of the cylinder.

[tex]\boxed{f_\text{normal}=f_\text{centrifugal}}[/tex]                                                  ...... (2)

The centrifugal force acting on the person's body is:

[tex]f_\text{centrifugal}=m\omega^2r[/tex]

Here, [tex]\omega[/tex] is the angular speed of the cylinder, [tex]r[/tex] is the radius of the cylinder.

Substitute [tex]m\omega^2r[/tex] for [tex]f_\text{centrifugal}[/tex] in equation (2).

[tex]N=m\omega^2r[/tex]

Substitute the value of [tex]N[/tex] in equation of static friction coefficient.

[tex]\begin{aligned}\mu&=\dfrac{mg}{m\omega^2r}\\&=\dfrac{g}{\omega^2r}\end{aligned}[/tex]

The acceleration due to gravity on the surface of Earth is [tex]9.81\text{ m}/\text{s}^2[/tex].

The angular speed of rotation of the cylinder is given as:

[tex]\begin{aligned}\omega&=2\pi\times\text{Revolutions per second}\\&=2\pi\times0.6\\&=3.77\text{ rad}/\text{s}\end{aligned}[/tex]

Substitute the values of [tex]\omega[/tex], [tex]g[/tex] and [tex]r[/tex] in above expression.

[tex]\begin{aligned}\mu&=\dfrac{9.81}{(3.77)^2\times2.5}\\&=\dfrac{9.81}{35.53}\\&=0.276\end{aligned}[/tex]

Thus, the minimum value of coefficient of static friction for which the person does not slide is [tex]\boxed{0.276}[/tex].

Learn More:

1. For typical rubber-on-concrete friction, what is the shortest time https://brainly.com/question/3017271

2. Motion in two dimensions https://brainly.com/question/1913142

3. the time taken by a car to accelerate on a friction surface https://brainly.com/question/7174363

Answer Details:

Grade: Senior school

Subject: Physics

Chapter: Circular motion

Keywords:

Amusement park, ride, spindle top, six flags, texas, vertical cylinder, hollow, 2.5m, 0.60 rev/s, dropped about, minimum static friction coefficient, rotation rate 0.60.

The pressure of an enclosed fluid on which force is applied is 150 N over an area of 10 cm² will be 1500 N/m² or 1500 Pa.

In the physical sciences, pressure is defined as the perpendicular force per unit area or the stress at a particular location within a confined fluid The force divided by the area over which it is exerted, or one-half pound per square inch, determines the pressure that a 42-pound box with an 84-square-inch bottom will impose on a surface.

Atmospheric pressure, which at sea level is roughly 15 pounds per square inch, is the amount of weight that the atmosphere exerts on each unit area of the Earth's surface. One pascal equals one newton per square meter when expressed in SI units, which is how pressure is calculated.

According to the question :

Pressure, P = F / A

P = 150 N

A = 10 cm² or

A = 0.1 m²

P = 150 / 0.1

P = 1500 Pa.

Hence, the Pressure on the enclosed fluid is 1500 Pa.

To get more information about Pressure :

https://brainly.com/question/15175692

#SPJ2

Final answer:

The change in internal energy of the system is 296 kJ, calculated using the first law of thermodynamics by adding the heat absorbed by the system (186 kJ) to the work done on the system by the surroundings (110 kJ).

Explanation:

The question involves the concept of change in internal energy of a system which is a part of thermodynamics in Chemistry. To determine the change in internal energy, we use the first law of thermodynamics, which states that the change in internal energy (ΔU) of a system is equal to the heat (Q) added to the system minus the work (W) done by the system on the surroundings.

In this case, the system absorbs 186 kJ of heat and the surroundings do 110 kJ of work on the system. As work is done on the system, it is treated as positive input of energy. Therefore, the change in internal energy (ΔU) for the system can be calculated as follows:

ΔU = Q + W

ΔU = 186 kJ + 110 kJ

ΔU = 296 kJ

The change in internal energy of the system is 296 kJ, assuming all quantities are in the same units (in this case, kilojoules).

Final answer:

If the pulley is not set parallel to the track, it will introduce a perpendicular component of the tension force, resulting in a reduction in the acceleration of the system. The normal force from the track will also increase, opposing the motion. This would be a systematic error as it stems from a consistent deviation from the correct setup.

Explanation:

If the pulley is not set so that the string is parallel to the track, it will introduce a component of the tension force that is perpendicular to the track. This perpendicular component will result in a normal force from the track which will oppose the motion of the system. Consequently, the acceleration of the system will be reduced. This effect can be understood by breaking down the tension force into components parallel and perpendicular to the track.

When the string is not parallel to the track, let's say at an angle theta, the tension force can be resolved into two components:

1. A component parallel to the track (T_parallel = T * cos(theta))

2. A component perpendicular to the track (T_perpendicular = T * sin(theta))

The parallel component (T_parallel) is responsible for providing the force that accelerates the system. The tension force is equal to the product of mass and acceleration (T_parallel = m * a). Therefore, any decrease in the parallel component of the tension force will result in a decrease in acceleration.

The perpendicular component (T_perpendicular) introduces a force perpendicular to the track, which is counterbalanced by the normal force from the track. As the angle theta increases, the normal force increases, opposing the motion and reducing the acceleration of the system.

This would be a systematic error because it is a consistent deviation from the correct setup. Systematic errors occur due to flaws in the experimental setup or technique. In this case, the error arises from the misalignment of the pulley and the track.

A ray is an ultrathin beam of light that travels in a straight line until it meets a reflecting or refracting surface. Geometric optics is the branch of physics that models the path of light as straight lines called rays.

A ray can be considered as an ultrathin beam of light that travels in a straight line until it meets a reflecting or refracting surface. In physics, the path of light is often modeled as straight lines called rays in the field of geometric optics. When light encounters objects several times larger than its wavelength, it behaves like a ray with subtle wave characteristics.

https://brainly.com/question/33230870

#SPJ11

Answer: Both are Brittle

Explanation:

Metals are lustrous, malleable and ductile. Metals are good conductors of heat and electricity.

Non-metals are poor conductors of heat and electricity. Non-metals are brittle and non-lustrous elements.

Elements which have properties between metals and non-metals are known as metalloids.

Some mettaloids are lustrous and conductors of electricity. One property that these elements share with non-metals is that these are brittle i.e. they can easily break.

The property metalloids share with nonmetals is [tex]\boxed{{\text{Both are brittle}}}[/tex].

Further explanation:

Nonmetals:

Elements that gain electrons in a chemical reaction are non-metals. They are the electronegative element that has high ionization energy. Non-metals are either gas, liquid or solid. Nonmetal oxides react with bases and form salts.

Properties of Nonmetals:

Physical State: Most non-metals exist in the form of gas and solid. The exception includes bromine that exists as liquid at room temperature.

Non-Malleable and Ductile: They are brittle and cannot be transformed into wires.

Conduction: Poor conductor of heat.

Luster: Non-metals have no metallic luster.

Melting and Boiling Point: Melting point of non-metals is lower than metals. Also, it is highly variable.

Metalloid:

An element that is a mixture of metals and nonmetals is called metalloids. The six known metalloids are boron, silicon, germanium, arsenic, antimony, and tellurium.

Properties of Metalloids:

Metalloids are metallic brittle solids.

Mostmetalloids are semiconductors and thermal conductors.

Some metalloids conduct electricity like metals.

1. Metalloids are brittle and also nonmetals are very brittle. Hence, both metalloids and nonmetals have this property. Hence option 1 is correct.

2. Metalloids can be either shiny or dull but nonmetals are dull. Hence, option 2 is incorrect.

3. Metalloids have melting points as similar to metals whereas nonmetals have melting points lower than metals. Hence, option 3 is incorrect.

4. Some metalloids conduct electricity like metals whereas nonmetal does not conduct electricity. Hence, option 4 is incorrect.

Learn more:

1. Calculate the equilibrium constant of pure water at  ? https://brainly.com/question/3467841

2. Calculate the wavelength of the electron: https://brainly.com/question/6352445

Answer details:

Grade: High School

Subject: Chemistry

Chapter: Metals and non-metals

Keywords: metalloids, brittle, lustrous, conductors, melting point, nonmetals, low, metals, high and shiny.

Electric motor

Answer:

A). Electric generator

Explanation:

One of the most significant properties of water is its ability to dissolve a wide variety of substances. Solutions in which water is properly the dissolving medium are called aqueous solutions. For electrolytes, water comes by the most primary solvent.  

Notes:

Keywords: classify, each of these soluble solutes, as a strong electrolyte, a weak, a nonelectrolyte. drag each item to the appropriate bin, acids, bases, dissolve, ionize, conduct electricity, water

The automobile taking approx. 178.54s (or around 3 minutes) while traveling 180ft is calculated using fundamental kinematic equations to determine constant acceleration and then time.

To solve this, we need to utilise some basic kinematic equations. First, let's find the acceleration using the formula a = (vf - vi)/s where vf = final velocity, vi = initial velocity, and s = displacement distance. Substituting in the provided values: a = (84ft/s - 72ft/s)/180ft = 0.067 ft/s².

Next, we use the equation t = (vf - vi) / a where t = time, vf = final velocity, vi = initial velocity, and a = acceleration. Substituting in the relevant values, we get t = (84ft/s - 72ft/s) / 0.067ft/s² ≈ 178.54s or approximately 3 minutes.

https://brainly.com/question/24458315

#SPJ12

the answer it actually 388800

The currents (Amperes) in the two cases are calculated as power/voltage: 

510000W / 12000V = 42.5 A 
510000W / 47000V = 10.85 A 

And that the power wasted in the two cases is calculated as current^2 x resistance:

(42.5 A)^2 (2.5 Ohms) = 4,515.625 W 
(10.85 A)^2 (2.5 Ohms) = 294.30625 W 

So the amount of power saved is the difference:
4,515.625 - 294.30625  = 4221.32 Watts

This is the main reason why distribution grids aim to operate at the highest voltages possible.

The direction of the resultant displacement of the dog is determined as 58.2⁰.

How to calculate the direction of the resultant displacement?

The direction of the resultant displacement of the dog is calculated by applying the following formula as shown below.

The sum of the x - component of the displacement;

Dx = 11 m  - 30 m x cos(55)

Dx = - 6.21 m

If the dog must end the run 10 m south of her original starting point, then the resultant displacement in y - direction is 10 m.

Dy = - 10 m

The direction of the resultant displacement of the dog is;

tan θ = Dy / Dx

tan θ = -10 / -6.21

tan θ = 1.61

θ = arc tan (1.61)

θ = 58.2⁰

Answer:

Radiation

Explanation:

Infrared radiation, that portion of the electromagnetic spectrum that extends from the long wavelength, or red, end of the visible-light range to the microwave range. ... Most of the radiation emitted by a moderately heated surface is infrared; it forms a continuous spectrum.

Answer: The correct answer is (d).

Explanation:

Magnet has two poles: South pole and North pole. The same poles of the magnets repel each other. The opposite poles of the magnets attract each other.

In the absence of other magnet, a freely swinging magnet points in North-South direction. The earth has a magnetic field. The magnetic field of the bar magnet is same as the magnetic field of the earth's magnet.

The position of  the earth's magnetic poles are not fixed. The south pole of the earth's magnet lies in the geographic north as it attracts the north pole of the freely swinging magnet.

If one part of a freely suspended magnet always points to Earth's magnetic pole in the Northern Hemisphere.

THE ANSWER IS D YOUR WELCOME:)