Answer:

Explanation:
given,
turntable rotate to, θ = 5 rad
time, t = 2.8 s
initial angular speed = 0 rad/s
final angular speed = ?
now, using equation of rotational motion



α = 1.28 rad/s²
now, calculation of angular velocity



hence, the angular velocity at the end is equal to 3.584 rad/s
It is actually caused by the environment, so its false. :)
Answer:
Friction
Explanation:
Friction is a force that slows down moving objects. If you roll a ball across a shaggy rug, you can see that there are lumps and bumps in the rug that make the ball slow down. The rubbing, or friction, between the ball and the rug is what makes the ball stop rolling. External Force is required.
Mechanical energy is the sum of kinetic energy and potential energy
The convection currents in the mantle caused the crust on top to break apart & go different directions.