It is given that by using track and cart we can record the time and the distance travelled and also the speed of the cart can be recorded. With all this data we can solve questions on the laws of motion.
Like using the first law of motion we can determine the force of gravity acting on the cart that has moved a certain distance and the velocity or the speed of card has already been registered and since time is known putting the values in formula would help us calculate the gravitational pull acting on cart.
Answer:

Explanation:
Given that:
Absolute temperature of the body, 
- emissivity of the body,

<u>Using Stefan Boltzmann Law of thermal radiation:</u>

where:
(Stefan Boltzmann constant)
Now putting the respective values:


As per kinematics equation we are given that

now we are given that
a = 2.55 m/s^2


now we need to find x
from above equation we have



so it will cover a distance of 93.2 m
Answer:
Explanation:
Wheel completes four revolution.
The linear displacement is zero.
The angular displacement is 4 x 2π = 8π radian.
So, option (c) is correct.
Answer:
a) 
b) 
c) Compressing is easier
Explanation:
Given:
Expression of force:

where:



when the spring is stretched
when the spring is compressed
hence,

a)
From the work energy equivalence the work done is equal to the spring potential energy:
here the spring is stretched so, 
Now,
The spring constant at this instant:



Now work done:



b)
When compressing the spring by 0.05 m
we have, 
<u>The spring constant at this instant:</u>



Now work done:



c)
Since the work done in case of stretching the spring is greater in magnitude than the work done in compressing the spring through the same deflection. So, the compression of the spring is easier than its stretching.