Question

A body of mass 0.1 kg falling freely under gravity takes 10 seconds to reach the ground calculate the kinetic energy and potential energy of the body when the body has travelled for 6 seconds

Answer 1

Answer:

Given: ,

From

kinetic energy of the body, when the body has travelled for seconds, is

K.E =

K.E =

To Find Potential Energy (PE):

Distance travelled by the body in sec, is

Distance travelled by the body in sec is

.

Answer 2

Given:

m = 0.1kg, t = 6seconds,

u = 0, a = g

To Find:

Kinetic energy and potential energy.

Solution:

Here, it is given that the mass of the body is $0.1kg$ falling under gravity and it takes $10seconds$ to reach the ground.

Firstly, we put the given values in $v=u+at$ .

Now, after putting the values in the above equation.

we get,

$v=0+9.8\times 6\\v=58.8ms^{-1}$

Here, the kinetic energy of the body, when it has traveled for 6 seconds is $K.E=\frac{1}{2}mv^{2}$

Now, after putting the given values in the above equation.

we get,

$K.E=\frac{1}{2}\times 0.1\times (58.8)^{2} \\K.E=172.9J$

So, the kinetic energy of the body is $172.9J.$

Now, the potential energy will be

$S_1_0=ut+\frac{1}{2}gt^{2}$

here, after putting the values in the above equation.

we get,

$S_1_0=0+\frac{1}{2}\times 9.8\times 10^{2}\\ S_1_0=490m.$

The distance traveled by the body in 6 seconds is,

$S_6=ut+\frac{1}{2}gt^{2} \\ =0+\frac{1}{2}\times 9.8\times 6^{2}\\ S_6=176.4m\\h=S_1_0-S_6\\=490-176.4=313.6m\\P.E=mgh\\=0.1\times 9.8\times 313.6\\=307.3J.$

Hence, the kinetic and potential energy of the body is 172.9J and 307.3J.