A boy pulls a sled 46 m across a flat field with a force of 120 N. The force acts on the sled through a rope at a 23° angle with the horizontal. What is the work the boy does on the sled? (Round your answer to two significant figures.)

Find the intensity i of the sound waves produced by one 60-w speaker at a distance of 1.0 m.

Once an object enters orbit, what keeps the object moving sideways? A) inertia B) gravity C) centripetal force D) air resistance

Sound waves are converted finally into which of these signals in order to be processed by the brain? A. Electrical signal waves B. pressure waves C. longitudinal waves D. high-frequency transverse waves E. low-frequency transverse waves

A remote control for a television works by sending out electromagnetic waves. Which is the best description for the behavior of the waves? a. The speed of the waves changes as it moves through the air, so the waves refract and diffract. b.

Will a change in the frequency of sound affect its speed?

A 2.1W iPod is used for 30 minutes. How much energy does it use?

How is the maunder minimum related to climate? a. changes in the earth's orbit correlate to changes in climate. b. unusually low sunspot activity correlates to unusually cold climatic events. c. the maunder minimum is unrelated to climate. d.

Why is thermal expansion an important consideration for engineering?

The stored energy an object has due to its position is potential energy. True or False?

Describe two changes of state that releases energy