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2 years ago

Define moment of momentum. at which condition is it's magnitude zero?

1 answer:

7 0

Let's start with the concept of momentum. What is it? Linear momentum in physics is mathematically written as a product of mass and velocity of an object. Now let us suppose a body of mass m is moving in an inertial frame of reference with velocity v. Consider the fact that no external force is acting on the system. The momentum of this body is given by mv, where m is the mass and v is its velocity. In case of simple real world problems not delving into the realms of relativity, mass is a conserved quantity and it cannot be zero. Hence the velocity of the body must be zero and hence the momentum.

However, photons are considered to have a rest mass zero.

However note the point carefully "rest mass". A body in motion cannot have mass to be zero.

<em>-</em><em> </em><em>BRAINLIEST</em><em> answerer</em><em> ❤️</em>

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Determine whether the variable is qualitative or quantitative. Favorite sport. Is the Variable Qualitative or Quantitative?

Over [174]

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3 years ago

A car is strapped to a rocket (combined mass = 661 kg), and its kinetic energy is 66,120 J.

aliina [53]

Answer:

9.43 m/s

Explanation:

First of all, we calculate the final kinetic energy of the car.

According to the work-energy theorem, the work done on the car is equal to its change in kinetic energy:

$W=K_f - K_i$

where

W = -36.733 J is the work done on the car (negative because the car is slowing down, so the work is done in the direction opposite to the motion of the car)

$K_f$ is the final kinetic energy

$K_i = 66,120 J$ is the initial kinetic energy

Solving,

$K_f = K_i + W = 66,120 + (-36,733)=29,387 J$

Now we can find the final speed of the car by using the formula for kinetic energy

$K_f = \frac{1}{2}mv^2$

where

m = 661 kg is the mass of the car

v is its final speed

Solving for v, we find

$v=\sqrt{\frac{2K_f}{m}}=\sqrt{\frac{2(29,387)}{661}}=9.43 m/s$

3 0

3 years ago

HELP PLEASE <br> Find the net force necessary for a 15 kg object to accelerate at 20 m/s/s.

tensa zangetsu [6.8K]

Answer:

<h3>The answer is 300 N</h3>

Explanation:

The force acting on an object given the mass and acceleration we use the formula

<h3>force = mass × acceleration</h3>

We have

force = 15 × 20

We have the final answer as

Hope this helps you

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2 years ago

A boy standing on the bridge kicks a stone into the water below. He kicks the stone with a horizontal velocity of 8.06 m/s. It l

Ronch [10]

Time taken to reach water :

$t = \dfrac{D}{v}\\\\t=\dfrac{6.78}{8.06}\ s\\\\t=0.84\ s$

Now, initial vertical speed , u = 0 m/s.

By equation of motion :

$h = ut +\dfrac{at^2}{2}$

Here, a = g = acceleration due to gravity = 9.8 m/s².

So,

$h = 0(t) +\dfrac{9.8\times 0.84^2}{2}\\\\h=3.46\ m$

Therefore, the height of the bridge is 3.46 m.

Hence, this is the required solution.

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3 years ago

The frequency of electromagnetic energy traveling through a medium can change if any of the following change EXCEPT: Select one:

agasfer [191]

Answer:

b. amplitude

Explanation:

An electromagnetic waveconsists of electrical oscillations and magnetic fields. The frequency of the wave is directly proportional to its energy and its speed and inversely proportional to its wavelength. Therefore, with the only magnitude with which it has no relation is with its amplitude.

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3 years ago

Define moment of momentum. at which condition is it's magnitude zero?​

Define moment of momentum. at which condition is it's magnitude zero?