How must a tennis serve start

Answer:

mass and distance

Explanation:

The force of gravity acting on a body depends on the mass of the body and the distance between the bodies.

This is based on Newton's law of Universal gravitation which states that "the force of gravity between two bodies is directly proportional to the  product of their masses and inversely proportional to the distance between them".

We see that the more the masses between two bodies, and the lower their separation the more the gravitational force between them.

Answer:

6m/s

Explanation:

The tangential velocity is the product of the linear velocity and the radius. This is expressed as;

v = wr

w is the angular velocity = 3rad/s

r is the radius = 2m

Substitute

v = 3 * 2

v = 6m/s

Hence the tangential velocity of the object is 6m/s

Answer:

3

Explanation:

i did it

Answer: 4

Explanation:

when energy is greater then frequency should increase and wavelength should decrease.

Therefore answer is 4

Answer:

104653.13J

Explanation:

Given parameters:

Mass of roller coaster  = 625kg

Speed  = 18.3m/s

Unknown:

Kinetic energy  = ?

Solution:

The kinetic energy is the energy due to the motion of a body.

     Kinetic energy  = [tex]\frac{1}{2}[/tex] x m x v²  

m is the mass

v is the speed

    Kinetic energy  =  [tex]\frac{1}{2}[/tex]  x 625  x  18.3²   = 104653.13J

Answer:

1. The velocity of the wagon decreases when Tradi is in the wagon because the mass increases while the external force stays constant.

2. The basic formula for calculating acceleration is a=F/a

Tommy along, acceleration: it will be 2.5 m/s^2. a=100/40

Tommy + Tradi = it will be about 1.66 m/s^2 since a=100/60

3. Well, you see, F=ma, when mass increases, the force decreases.

The relationship between mass and force is inversely proportional.

According to the graphs, velocity increases when there's less mass, which you could say that they are also inversely proportional.

Another comparison,

As the force applied on an object increases, when the mass stays constant, the acceleration also increases. Which means that they are directly proportional.

Answer:

[tex]Va-Vb=168KV[/tex]

Explanation:

From the question we are told that

Two points charge of 4\mu C and 2\mu C

Generally we find the  Va and Vb individually to find there difference

Given a rectangle with two equal sides each,Assume lengths for bot sides

Length L=0.3

Breath B=0.4

Diagonal D=[tex]\sqrt{0.3^2+0.4^2} =0.5[/tex]

at  opposite sides

Mathematically Va can represented as

[tex]Va =k(\frac{4*10^_-_6}{0.3} +\frac{-2*10^_-_6}{0.5} )[/tex]

[tex]Va =9*10^9(\frac{4*10^_-_6}{0.3} +\frac{-2*10^_-_6}{0.5} )[/tex]

[tex]Va =9*10^9(0.00001333333-0.000004} )[/tex]

[tex]Va =84000V[/tex]

[tex]Va =84KV[/tex]

Mathematically Vb is  represented as

[tex]Va =k(\frac{-4*10^_-_6}{0.3} +\frac{2*10^_-_6}{0.5} )[/tex]

[tex]Va =9*10^9(\frac{-4*10^_-_6}{0.3} +\frac{+2*10^_-_6}{0.5} )[/tex]

[tex]Va =9*10^9(-0.00001333333+0.000004} )[/tex]

[tex]Va =-84000V[/tex]

[tex]Va =-84KV[/tex]

Therefore

[tex]Va-Vb=84-(-84)\\Va-Vb=84+84\\Va-Vb=168KV[/tex]

Answer: Three forces act significantly on a freely floating helium-

filled balloon: gravity, air resistance (or drag force), and a

buoyant force.

Explanation:

The air pressure on the bottom of the balloon is slightly higher than the air pressure on the top of the balloon (because of the altitude difference). This difference gives rise to the bouyant force. This force competes with gravity as the two main forces acting on the balloon. Every time your feet hit the ground when you are running, the ground hits your feet with an equal and opposite force. Newton’s third law explains how balloons and rocket engines work. When the neck of an inflated balloon is released, the stretched rubber material pushes against the air in the balloon. The air rushes out of the neck of the balloon.

Answer:

d)energy

Explanation:

Waves can transfer energy over distance without moving matter the entire distance. For example, an ocean wave can travel many kilometers without the water itself moving many kilometers. The water moves up and down—a motion known as a disturbance. It is the disturbance that travels in a wave, transferring energy.

Answer:

motion of an object—even if the object is maintaining a constant speed—still count as acceleration

Explanation:

Answer:

10 mph

Explanation:

Answer:

The electric field outside the sphere will be [tex]\dfrac{qr}{4\pi\epsilon_{0}R^3}[/tex].

Explanation:

Given that,

Radius of solid sphere = R

Charge = q

According to figure,

Suppose r is the distance between the point P and center of sphere.

If [tex]\rho[/tex] be the volume charge density,

Then, the charge will be,

[tex]q=\rho\times\dfrac{4}{3}\pi R^3[/tex].....(I)

Consider a Gaussian surface of radius r.

We need to calculate the electric field outside the sphere

Using formula of electric field

[tex]\oint{\vec{E}\cdot \vec{dA}}=\dfrac{Q}{\epsilon_{0}}[/tex]

[tex]E\times4\pi r^2=\dfrac{\rho\dotc \dfrac{4}{3}\pi r^3}{\epsilon_{0}}[/tex]

Put the value from equation (I)

[tex]E\times4\pi r^2=\dfrac{qr^3}{\epsilon_{0}R^3}[/tex]

[tex]E=\dfrac{qr}{4\pi\epsilon_{0}R^3}[/tex]

Hence, The electric field outside the sphere will be [tex]\dfrac{qr}{4\pi\epsilon_{0}R^3}[/tex].

Answer:

(Total initial linear momentum = total final linear momentum.)

Momentum = mass × velocity

180×4 + 120×0 = 180×0 + 120×V

(180 ×4)/120 = V

Answer:  2.75 kg*m/s

========================================

Explanation:

I'll use these variables

though as shown below, we have the time variable cancel out

F = ma .... newton's second law

F = m*(v/t)

i = F*t

i = m*(v/t)*t

i = m*v

The impulse is the product of mass and velocity

In this case, we have

So,

i = m*v

i = (0.125 kg)*(22 m/s)

i = (0.125*22) kg*m/s

i = 2.75 kg*m/s

This is equivalent to 2.75 Ns where "Ns" is an abbreviation of "Newton seconds". It's effectively multiplying the Newton unit with the seconds unit.

The impulse is the change in momentum. So the snowball has a change of momentum of 2.75 kg*m/s

Answer:

A,C

Explanation:

The amount of time it takes for a wave to return can be used to create an image

High--frequency sound waves are reflected by tissues in the body

Ultrasound technology produces an image of part of the body on: The amount of time it takes for a wave to return can be used to create an image and high-frequency sound waves are reflected by tissues in the body. So, option (A) and (C) is correct.

Sound waves are used in ultrasound imaging to create images of the inside of the body. It aids in determining the origins of discomfort, edema, and infection in the body's internal organs as well as the examination of a developing fetus in pregnant women.

The same concepts underlie sonar used by ships, bats, and fisherman as well as those used by ultrasound imaging. A sound wave echoes or bounces back when it encounters an object. These echo waves can be measured to obtain information on the object's size, shape, and consistency as well as its distance from the source. Whether the thing is solid or liquid is included in this.

The amount of time it takes for a wave to return helps to create an image and high-frequency sound waves are reflected by tissues in the body. So, option (A) and (C) is correct.

To find more about ultrasonic, refer the link:

https://brainly.com/question/21336084

#SPJ5

Answer:

Rebound

Explanation:

Answer:

Rebound is your answer

Explanation:

To rebound is to bounce or

spring back after coming into

contact with another object.

Examples:

Rebound

• A basketball rebounds off the

backboard.

• A hockey puck rebounds off

the wall.

Answer:

fr = R× co-efficient

= 755 × 0.80  

= 604N

Explanation:

Answer:

-0.55m/s

Explanation:

Given that: For the boy

Weight = 745N

Velocity = +0.35 m/s

Mass of the boy = ?

g = 9.81m/s^2

W = mg

745 = m×9.81

m = 75.94kg

For the girl

Given that:

Weight = 477 N

g = 9.81m/s^2

m = ?

W = mg

477 = m×9.81m/s^2

m = 48.62kg

To solve for the v of the girl, the two has to add up

48.62kg×v + 75.94kg×+0.35 m/s = 0

48.62v + 26.579 = 0

48.62v = - 26.579

v = -26.579/48.62

v = -0.5466

v = -0.55m/s

Hence, the velocity of the girl is -0.55m/s.

The negative sign is as a result of the two of them moving is opposite direction.

Answer:

It's the number of protons in the nucleus of the atom

Answer:

E = 105.84  J

Explanation:

Given that,

Mass of cat, m = 3.6 kg

It is laying 3 meters above the ground.

We need to find the cat's potential energy. The formula for the potential energy of an object is given by :

E = mgh

Substituting all the values,

E = 3.6 kg × 9.8 m/s²×3 m

E = 105.84  J

So, the cat's potential energy is 105.84  J.

Answer:

0J

Explanation:

No work is being done on the wall by the man pushing on it.

 Given parameters:

Mass of man  = 75kg

Mass of wall  = 500000kg

Time  = 250s

Unknown:

Work done  = ?

Solution:

Work done is the force applied on a body that moves it along a particular path.

For work to be done, distance must be move or displacement must occur.

Since the wall is not moving the distance is 0;

    Work done  = Force x distance

Since distance is 0m, work done is 0J

The work done on the wall by the man is 0 J.

To calculate the amount of work done by the man, we use the formula below.

Formula:

Where:

from the question,

Given:

Substitute these values into equation 1

Hence, the work done on the wall by the man is 0 J.

Learn more about work done here: https://brainly.com/question/8119756

Answer:

Polarization occurs when an electric field distorts the negative cloud of electrons around positive atomic nuclei in a direction opposite the field. Polarization P in its quantitative meaning is the amount of dipole moment p per unit volume V of a polarized material, P = p/V.

Explanation:

Answer:

Polarization occurs when an electric field distorts the negative cloud of electrons around positive atomic nuclei in a direction opposite the field. Polarization( P) in its quantitative meaning is the amount of dipole moment (p) per unit volume V of a polarized material, where P = p/V.

Answer:

can someone please answer this i need this for a mastery test aswell

Explanation:

it would be very appreciated

Answer:

3.45 inches = 8.763e-5 kilometers

Answer:

at a rate of deceleration of -15 kilometers per second

Explanation:

90/6=15

The rate of deceleration when a car goes from 90km/h to 0 in 6 seconds is 4.16m/s².

The rate of deceleration can be calculated by using the following formula:

d = v - u/t

Where;

d = 25 - 0/6

d = 4.16m/s²

Therefore, the rate of deceleration when a car goes from 90km/h to 0 in 6 seconds is 4.16m/s².

Learn more about deceleration at: https://brainly.com/question/4403243

Motion energy is indeed the total of kinetic and potential energies in a workable item. The energy contained in moving things is known as motion energy.

In physics, energy is the capacity to accomplish work. It can be potential, kinetic, thermal, electric, chemical, radioactive, or in other forms. There is also heat and work, which is energy inside the process of being transferred through one body to the other. Energy is always classified according to its type once it has been transmitted.

The energy contained in moving things is known as motion energy, sometimes known as mechanical energy. More energy is saved when the thing goes quicker. Motion energy is indeed the total of kinetic and potential energies in a workable item.

Therefore, motion energy is indeed the total of kinetic and potential energies in a workable item.

To learn more about energy, here:

https://brainly.com/question/29763772

#SPJ2

Answer:

18 newtons

Explanation:

Divide weight by speed

The total energy of all the particles makes up thermal energy. This implies that larger objects with slower-moving particles at low temperatures can have more energy than smaller ones with higher temperatures.

Thermal energy is the sum of the energies of all the particles. This implies that larger objects at low temperatures can have more energy than smaller ones at higher temperatures due to slower-moving particles.

These molecules and atoms move more quickly when something is heated, providing it with more thermal energy. Compared to cold water, hot water has more thermal energy.

Therefore, molecules and atoms in colder objects move more slowly and have less thermal energy than those in warmer ones. The ability of particles to transfer energy increases with speed.

To learn more about thermal energy, refer to the below link:

https://brainly.com/question/11278589

#SPJ2