Well, the relationship between the net force and mass and acceleration of an object are directly related, as per the equation - Fnet = ma.
Thus the solution is A. As the net force of an object decreases, the object's acceleration also decreases, mass is kept constant.
Answer:

Explanation:
According to the law of conservation of linear momentum, the total momentum of both pucks won't be changed regardless of their interaction if no external forces are acting on the system.
Being
and
the masses of pucks a and b respectively, the initial momentum of the system is

Since b is initially at rest

After the collision and being
and
the respective velocities, the total momentum is

Both momentums are equal, thus
Solving for 


The initial kinetic energy can be found as (provided puck b is at rest)


The final kinetic energy is


The change of kinetic energy is

Answer:
The Skater's final angular speed =8rad/s
Explanation:
Let initial momentum of inertia be I1
Let final momentum of inertia be I2
But I2= I1/2
It is decreased by one-half
There is no external torque on the system, therefore
I1w1=I2w2
I1×4=(I1/2)×w2
Dividing through by I1 on both sides leaves you with:
4=w2/2
Cross multiply
W2=4×2=8rad/s