g A ping pong ball (thin shell sphere) rolls down an incline at 30° from rest. What is its acceleration

Explanation:

According to newtons second law of motion;

F = ma 1

Also the force acting aong the inclines is expressed as;

F = mgsintheta

m is the mass of the object

a is the acceleration

theta is angle of inclination

Equate 1 and 2

ma = mg sin theta

a = gsin(theta)

a = 9.8sin30

a = 9.8(0.5)

a = 4.9m/s²

Hence the acceleration of the ping pong is 4.9m/s²

answer: the metamorphic rocks are formed when they are exposed to high pressure and high temperatures. this happens when one of the earth's plates comes in contact with the other plate by traveling in opposite directions, straight into each other or slipping under one another. the friction that is caused by this activity results in   melting of rocks and when it cools they are known as metamorphic rocks. this process needs a controlled amount of pressure and temperature otherwise it may turn into magma.

3. dark matter

empty space could also be a simple vacuum