A heat engine produces 8200 j of heat while performing 3200 of useful work. what is the efficiency of this engine? (i'm doing something wrong.)

DC versus AC problem. Suppose your DC power supply is set to 15 V and the vertical setting on the oscilloscope is at 5 V/div.

At time t=0 a 2150 kg rocket in outer space fires an engine that exerts an increasing force on it in the + x-direction. This force obeys the equation Fx=At2, where t is time, and has a magnitude of 893.68 N when t=1.25 s.

What quantities determine the resistance of a piece of material? Choose all that apply. The voltage across the materialThe type of materialThe current flowing through the piece of materialThe cross-sectional area of the piece of materialThe length

A dog pulls on his leash with a 10-n force to the left, but doesn't move. identify the reaction force.

If a direct relationship exists between Variable A and Variable B, what would happen to Variable B if Variable A is increased? It will increase too. It will decrease. It will go up and down in a cycle. It will respond randomly.

What has become an important alternative to Piagetian approaches?

How would life on earth be different if earth's axis were not tilted with respect to its orbit? A. There would be no seasons. B. There would be no day and night. C. All places would have the same climate. D. The seasons would be much shorter.

What will a spring scale read for the weight of a 75.0-kg woman in an elevator that moves upward with constant speed of 5.8 m/s?

What's the definition of: • cellular respiration • photosynthesis

What are the steps that are important to take for your safety during an earthquake? a. stay away from walls and windows c. stay away from electrical and gas lines b. get under a desk or table d. all of the above