Answer:

Explanation:
<u>Motion With Constant Acceleration
</u>
It's a type of motion in which the velocity of an object changes uniformly over time.
The equation that describes the change of velocities is:

Where:
a = acceleration
vo = initial speed
vf = final speed
t = time
Solving the equation for a:

The ball starts at rest (vo=0) and rolls down an inclined plane that makes it reach a speed of vf=7.5 m/s in t=3 seconds.
The acceleration is:


Answer:
E) momentum and mechanical energy
Explanation:
In the context, an object is attached to the another mass with a spring which is initially at a rest position. Now when the spring is compressed, the two masses moves with the same speed. Now since the both the masses combines with the spring to move together they are considered as one system and in this case the momentum and the kinetic energy will be conserved.
The kinetic energy and momentum of the system after collision and the kinetic energy and momentum of the two masses before collision will be constant.
112/2.63= 42.586
42.586 is your answer I need 20 characters