Answer:
The acceleration of the sled is
.
Explanation:
It is given that,
Initial speed of sled is 0 because it was at rest.
It is placed at an angle of 28° on a frictionless hill.
We need to find the acceleration of the sled. It is placed at an incline. It means that the acceleration of the sled is given by :

So, the acceleration of the sled is
.
Answer:

Explanation:
Given,
mass of the object,m = 0.30 Kg
initial speed, v_i = 3 m/s
time of collision = 0.20 s
final speed, v_f = -4 m/s
Impulse = change in momentum



Hence, impulse of the object is equal to 
it is also known as formula for circumfrence which is 2 times pi times radius. if radius was 5 then the circumfrence would be 10pi.