When scientists state that energy transformation are inefficient, do they mean energy is destroyed? Explain why.

If one doubles the emfs in a circuit and doubles the resistances in the circuit at the same time, what happens to the currents through the resistors? Assume there are only emfs and resistors in the circuit.

A neuron transfers information in the form of an electrical impulse. a. True b. False

Which of the following is an example of how a scientist might use a model? A. Marbles placed inside a hollow sphere are used to describe protons in a nucleus B. A wrench is used to tighten a nut onto a piece of wood C.

A cart is pushed at a supermarket for a distance of 30 m South, then 15 m West and finally 5 m West. This entire motion lasts for 30 minutes.

A sky diver steps from a high-flying helicopter. if there were not air resistance, how fast would she be falling at the end of a 12 second jump?

Why does ice generally have very little friction when it is in contact with other materials?

A stationary speed gun emits a microwave beam at 2.10*10^10Hz. It reflects off a car and returns 1030 Hz higher. What is the speed of the car?

Discuss the changes in potential energy and kinetic energy and total energy for skateboarder going up and down on a half pipe ramp

The diagram below shows rock is affected when water enters cracks in rock, freezes and becomes ice

A vertical piston-cylinder device contains a gas at a pressure of 100 kPa. The piston has a mass of 5 kg and a diameter of 12 cm. Pressure of the gas is to be increased by placing some weights on the piston.