Answer:The mass of ball B is 10 kg.
Explanation;
Mass of ball A = 
Velocity of the ball A before collision:
Velocity of ball A after collision=
Mass of ball B= 
Velocity of the ball B before collision:
Velocity of ball B after collision=



The mass of ball B is 10 kg.
Answer:
it have Potential energy
Explanation:
given data
Drag the pendulum to an angle 30∘
to find out
what form of energy does it have
solution
we know that pendulum start no kinetic energy when it release from any rest position then in starting it have potential energy only so that when pendulum is angle 30∘ at some height from ground so when it start it have potential energy same as in starting.
we know that the total energy is always conserve
so it have potential energy
True
From what Ive learned its like how you create your own hypothesis for a science experiment it may not work completely that way but you learn what didnt work and what does work
They will create an alternative and more efficient way of using natural resources.