An electric motor converts electrical energy into blank energy

What is a good example of instantaneous speed

What is the force that opposes motion and works against the downward pull? a) friction b) gravity c) weight d) acceleration

Vi. on another planet, a spring with constant 4.7 n/m is set up and allowed to expand verticaly freely. 8.4kg mass is placed on the spring and the spring extends 5.28m. calculate the exected extension on earth.