Question

3. You drop a 5 kg ball from a height of 2 m. Just before it reaches the ground, calculate how much kinetic energy does it have? Describe how you arrive at your answer.

Answer 1

Answer: i hope this is the right answer

Explanation: At the height of 2 m, K.E is 0 J and potential as mgh=5*2*10=100 J. Hence at lowest height, the Potential energy should be converted into the kinetic. Hence, the KE of the ball should be 100 J just before touching the ground.

Answer 2

Concept:

Kinetic energy is defined as a kind of energy that an object or a particle has by reason of its motion.

The acceleration of freely falling bodies due to the force of attraction of the opposite body is known as acceleration due to gravity.

Given:

The mass of the ball is $5kg$ and the height from which it is dropped is $2m$.

Find:

The kinetic energy of the ball.

Solution:

Mass of the object, $m=5kg$.

The height of the ball, $h=2m$.

As the ball is in free fall, the acceleration will be acceleration due to gravity.

$g=9.8m/s^2$

Now, the kinetic energy is given as:

$K.E=mgh\\K.E=5\times9.8\times2\\K.E=98J$

Hence, the kinetic energy of the ball is $98J$.

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