Aconstant magnetic flux through a closed loop of wire induces an emf in that loop. true or false?

False

Explanation: In order to explain this problem we have to use the Faraday law, which say

dФm/dt=-ε  it means that the variation of the magnetic field flux with time is equal to the emf ( electromotive force). In our case the magnetic flux is constant then there is not a emf induced in a wire closed loop.

prolly a beacuse the momentuem the car has increases while going down hill

b. lifting dumbbell weight at 20-degree angle from the body after a 45-degree angle