60 RPM equals one hertz (i.e., one revolution per second, or a period of one second). The SI unit for period is the second.
Yes, It has a stored energy in that stone.
Answer:
68cm
Explanation:
You can solve this problem by using the momentum conservation and energy conservation. By using the conservation of the momentum you get

m: mass of the bullet
M: mass of the pendulum
v1: velocity of the bullet = 410m/s
v2: velocity of the pendulum =0m/s
v: velocity of both bullet ad pendulum joint
By replacing you can find v:

this value of v is used as the velocity of the total kinetic energy of the block of pendulum and bullet. This energy equals the potential energy for the maximum height reached by the block:

g: 9.8/s^2
h: height
By doing h the subject of the equation and replacing you obtain:

hence, the heigth is 68cm
They have the same velocity because their displacements (shortest line from point A to point B, which is a straight line) are the same and they meet at the same time.
Answer:
No
Explanation:
All planets are different than others and bigger so that means no