Convection currents form when warm air rises and cold air sinks. What causes the warm air to rise and the cold air to sink? A. chemical energy B. activation energy O C. a difference in density D. the law of conservation

Why don't you see your reflection in water with waves or repples

What is the magnitude of the acceleration vector which causes a particle to move from velocity −5i−2j m/s to −6i+ 7j m/s in 8 seconds. answer in m/s.

The system is released from rest with the cable taut, and the homogeneous cylinder does not slip on the rough incline. determine the angular acceleration of the cylinder and the minimum coeffi cient s of friction for which the cylinder will not slip.