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4 years ago

Find the kinetic energy of a bullet weighing 0.10 N if its velocity is 2.0 X 103 m/s?

Physics

1 answer:

irina1246 [14]4 years ago

5 0

The kinetic energy of the bullet is 20.4 kJ.

<u>Explanation:</u>

Kinetic energy of a bullet will be equal to the product of mass of the bullet with the square of velocity or speed of the bullet and then the half of that product value.

But here the mass of the bullet is not given, instead the weight of the bullet is given in terms of force. So from this, we have to first find the mass of the bullet.

We know that as per Newton's second law of motion, force is directly proportional to the product of mass and acceleration. So here the acceleration will be equal to the acceleration due to gravity as it is weight of the object.

So F = mg

0.10 N = m × 9.8

So ,the mass of the bullet is 0.0102 kg.

Now, we know the mass and velocity of the bullet is given as 2000 m/s.

So,

kinetic energy = $\frac{1}{2}$ × m × v²

kinetic energy = 0.5 × 0.0102 × 2000 × 2000 = 20.4 kJ

Thus, the kinetic energy of the bullet is 20.4 kJ.

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A space rover weighs less on Mars than it does on Earth. Which statement explains this difference? A. The gravitational constant

Maksim231197 [3]

Answer:

B. The mass of Mars is less than the mass of Earth.

Explanation:

Mass of an object is the constant anywhere in the universe.

The weight of an object is equal to the gravitational force acting on it.

Weight is given by

$W=\dfrac{GMm}{R^2}\\\Rightarrow W=\dfrac{GM}{R^2}m\\\Rightarrow W=mg$

where

G = Gravitational constant

M = Mass of Planet

R = Radius of planet

m = Mass of object

g = Acceleration due to gravity

So weight of an object depends on the acceleration due to gravity on that planet. The acceleration due to gravity depends on the mass and radius of the planet.

The weight of the object is less on Mars because mars has less mass compared to Earth.

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3 years ago

A mouse ran 25 meters in 5 seconds, stopped for 10 seconds to eat a piece of cheese, and finally ran another 5 seconds a distanc

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Answer:

It ran at an average of 2 meters per second.

Explanation:

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3 years ago

A horizontal power line carries a current of 7250 A from south to north. Earth's magnetic field (65.7 µT) is directed toward the

gogolik [260]

Answer:

a) $||\vec F_{B}||=62.664\,N$ , b) From east to west.

Explanation:

Vectorially, the magnetic force can be calculed by the following formula:

$\vec F_{B} = i\cdot \vec l\, \times \, \vec B$

The cross product is:

$\vec F_{B} = \left|\begin{array}{ccc}i&j&k\\1015000\,A\cdot m&0\,A\cdot m&0\,A\cdot m\\22.471\times 10^{-6}\,T&-61.738\times 10^{-6}\,T&0\,T\end{array}\right|$