All categories

2 years ago

Kinetic energy and mass are ________ proportional.

Physics

2 answers:

omeli [17]2 years ago

9 0

Answer:

The Kinetic energy and mass are _directly_ proportional.

Explanation:

We know that Kinetic Energy is basically termed as the capacity of a body to do work.

Kinetic energy is often used to associate with moving objects, therefore, K.E is normally termed as the energy of motion.

The formula of K.E of an object of mass and velocity is defined

K.E = 1/2mv²

From the formula, it is clear that K.E is directly proportional to its mass and also directly proportional to the square of its velocity.

For example,

If A toy plane with a mass of 10 kg is flying at 20 m/s. Its K.E will be:

m = 10 kg

v = 20 m/s

K.E = 1/2mv²

= 1/2(10)(20)²

= 1/2(10)(400)

= 5(400)

= 2000 J

Now, let suppose, if we double the mass of a toy plane i.e.

m = 20 kg

K.E = 1/2mv²

= 1/2(20)(20)²

= 1/2(20)(400)

= 10(400)

= 400 J

Therefore, the K.E is doubled when doubled the mass.

Therefore, the Kinetic energy and mass are _directly_ proportional.

sladkih [1.3K]2 years ago

8 0

Answer:

directly

Explanation:

You might be interested in

It is observed that the time for the ball to strike the ground at b is 2.5 s. determine the speed at which the ball was thrown.

Alika [10]

Ergrexgehtenhyrnsehtrsjyrrsjjrt

6 0

2 years ago

How is a family defined

natulia [17]

Answer:Family

Explanation: Family is defined as people you love, people that you can count on. People that make you happy. Family isnt only people who are related to you by blood, we are all a family. Certain people are your family.

3 0

3 years ago

A flat disk of radius 0.50 m is oriented so that the plane of the disk makes an angle of 30 degrees with a uniform electric fiel

nexus9112 [7]

Answer:

The electric flux is $280\ \rm N.m^2/C$

Explanation:

Given:

Radius of the disc R=0.50 m
Angle made by disk with the horizontal $\theta=30^\circ$
Magnitude of the electric Field $E=713.0\ \rm N/C$

The flux of the Electric Field E due to the are dA in space can be found out by using Gauss Law which is as follows

$\phi=\int E.dA$

where

$\phi$ is the total Electric Flux
E is the Electric Field
dA is the Area through which the electric flux is to be calculated.

Now according to question we have

$=EA\cos\theta \\=713\times 3.14\times 0.5^2 \times \cos60^\circ\\=280\ \rm N.m^2/C$

Hence the electric flux is calculated.

8 0

3 years ago

What advantage do space telescopes have over telescopes used on earth?

Elina [12.6K]

Earth's atmosphere blocks many types of light including gamma, x-rays most ultraviolet and infrared. So optical telescopes that use visible light and ultraviolet telescopes that are used to study very hot stars are much less effective on Earth.

4 0

3 years ago

Read 2 more answers

Physics B 2020 Unit 3 Test

weqwewe [10]

Answer:

When a charge is in motion in a magnetic field, the charge experiences a force of magnitude

$F=qvB sin \theta$

where here:

For the proton in this problem:

$q=1.602\cdot 10^{-19}C$ is the charge of the proton

v = 300 m/s is the speed of the proton

B = 19 T is the magnetic field

$\theta=65^{\circ}$ is the angle between the directions of v and B

So the force is

$F=(1.602\cdot 10^{-19})(300)(19)(sin 65^{\circ})=8.28\cdot 10^{-16} N$

The magnetic field produced by a bar magnet has field lines going from the North pole towards the South Pole.

The density of the field lines at any point tells how strong is the magnetic field at that point.

If we observe the field lines around a magnet, we observe that:

- The density of field lines is higher near the Poles

- The density of field lines is lower far from the Poles

Therefore, this means that the magnetic field of a magnet is stronger near the North and South Pole.

The right hand rule gives the direction of the force experienced by a charged particle moving in a magnetic field.

It can be applied as follows:

- Direction of index finger = direction of motion of the charge

- Direction of middle finger = direction of magnetic field

- Direction of thumb = direction of the force (for a negative charge, the direction must be reversed)

In this problem:

- Direction of motion = to the right (index finger)

- Direction of field = downward (middle finger)

- Direction of force = into the screen (thumb)

The radius of a particle moving in a magnetic field is given by:

$r=\frac{mv}{qB}$

where here we have:

$m=6.64\cdot 10^{-22} kg$ is the mass of the alpha particle

$v=2155 m/s$ is the speed of the alpha particle

$q=2\cdot 1.602\cdot 10^{-19}=3.204\cdot 10^{-19}C$ is the charge of the alpha particle

B = 12.2 T is the strength of the magnetic field

Substituting, we find:

$r=\frac{(6.64\cdot 10^{-22})(2155)}{(3.204\cdot 10^{-19})(12.2)}=0.366 m$

The cyclotron frequency of a charged particle in circular motion in a magnetic field is:

$f=\frac{qB}{2\pi m}$

where here:

$q=1.602\cdot 10^{-19}C$ is the charge of the electron

B = 0.0045 T is the strength of the magnetic field

$m=9.31\cdot 10^{-31} kg$ is the mass of the electron

Substituting, we find:

$f=\frac{(1.602\cdot 10^{-19})(0.0045)}{2\pi (9.31\cdot 10^{-31})}=1.23\cdot 10^8 Hz$

When a charged particle moves in a magnetic field, its path has a helical shape, because it is the composition of two motions:

1- A uniform motion in a certain direction

2- A circular motion in the direction perpendicular to the magnetic field

The second motion is due to the presence of the magnetic force. However, we know that the direction of the magnetic force depends on the sign of the charge: when the sign of the charge is changed, the direction of the force is reversed.

Therefore in this case, when the particle gains the opposite charge, the circular motion 2) changes sign, so the path will remains helical, but it reverses direction.

The electromotive force induced in a conducting loop due to electromagnetic induction is given by Faraday-Newmann-Lenz:

$\epsilon=-\frac{N\Delta \Phi}{\Delta t}$

where

N is the number of turns in the loop

$\Delta \Phi$ is the change in magnetic flux through the loop

$\Delta t$ is the time elapsed

From the formula, we see that the emf is induced in the loop (and so, a current is also induced) only if $\Delta \Phi \neq 0$ , which means only if there is a change in magnetic flux through the loop: this occurs if the magnetic field is changing, or if the area of the loop is changing, or if the angle between the loop and the field is changing.