Which event is an example of a contact force?

A.

a nail being attracted to a magnet

B.

a leaf falling from a tree

C.

an electric charge jumping from a sweater to a person

D.

a person pulling a sled

What determines if an object is moving?

A student is using a 98 ohm resistor to build a circuit with a voltage source. If the student needs 0.54 amperes of current to flow through the resistor, what voltage should be used?

A carnot heat engine has an efficiency of 0.800. if it operates between a deep lake with a constant temperature of 280.0 k and a hot reservoir, what is the temperature of the hot reservoir?

A makeshift swing is constructed by making a loop in one end of a rope and tying the other end to a tree limb.

Tidal-power-generating facilities are common worldwide. True False

Which of the following best describes a mechanical wave? A. A periodic disturbance of a medium. B. A movement of matter. c. A transfer of energy. D. When energy is converted from one form to another.

What is a 2d game. Give a refrence.

Two exactly similar wire of steel and copper are stretched by equal force. if the total elongation is 10cm. find how much each wire is elongated given young's modules for steel = 2*10^10 N/M^2 and Young's modules for copper 2*10^10N/M^2.

Which of the following is the FINAL step in a forecasting system? A. Validate and implement the results. B. Make the forecast. C. Select the forecast model (s). D. Gather the data needed to make the forecast.

Resistors in parallel together contain less resistance than resistors in series together. Create an analogy to explain this phenomena and post it here.