Answer:
Option A
Explanation:
From the question we are told that:
Mass 
Velocity 
Generally the equation for momentum for Ball A is mathematically given by
Initial Momentum



Final Momentum

Therefore

Generally the equation for momentum for Ball B is mathematically given by
Initial Momentum



Final Momentum

Therefore

Option A
Answer:
15.4 kg.
Explanation:
From the law of conservation of momentum,
Total momentum before collision = Total momentum after collision
mu+m'u' = V(m+m').................... Equation 1
Where m = mass of the first sphere, m' = mass of the second sphere, u = initial velocity of the first sphere, u' = initial velocity of the second sphere, V = common velocity of both sphere.
Given: m = 7.7 kg, u' = 0 m/s (at rest)
Let: u = x m/s, and V = 1/3x m/s
Substitute into equation 1
7.7(x)+m'(0) = 1/3x(7.7+m')
7.7x = 1/3x(7.7+m')
7.7 = 1/3(7.7+m')
23.1 = 7.7+m'
m' = 23.1-7.7
m' = 15.4 kg.
Hence the mass of the second sphere = 15.4 kg
A. when it reaches the top of its flight
potential energy increases as the height of the object does, and the highest point of a ball's flight is when it reaches the top.
you take a length of ordinary wire, make it into a big loop, and lay it between the poles of a powerful, permanent horseshoe magnet. Now if you connect the two ends of the wire to a battery, the wire will jump up briefly.When an electric current starts to creep along a wire, it creates a magnetic field all around it. If you place the wire near a permanent magnet, this temporary magnetic field interacts with the permanent magnet's field.
Molecules of liquid are far away from each other but less compared to gas. Liquid has the ability to flow. Liquid molecules can move. Liquid occupies the shape of the container. Thus, they do not have fixed shape. Liquid has fixed volume because they are not compressible(easily)