Do electromagnetic waves travel through a medium

Why did J. J. Thomson experiment with cathode ray tubes?

Two children are playing with a roll of paper towels. One child holds the roll between the index fingers of her hands so that it is free to rotate, and the second child pulls at constant speed on the free end of the paper towels.

An automobile use a 75,000 J of chemical energy from Gosselin produce 10,000 J of useful output energy A. calculator it's efficiency B. where does the lost energy go, that part of the input work that doesn't become useful work?

When a firefighter slides down a pole his mechanical energy is transformed into thermal energy because of

How much voltage will Gabriel need to produce a 3 ampere current through a 37 ohm resistor? a 111 V b 34 V c 0.08 V d 12.33 Volts e 28 Volts

Sound travels 2146 m through a material in 1.4 seconds. What is the material?

What two pieces of data indicates that uranus resides in the outer layer of the solar system.

What is acceleration? a. change in velocity/change in time b. change in distance/change in time c. change in mass/change in volume d. change in pressure/change in time

Brittany stands at rest on a skateboard. the combined mass of brittany and the skateboard is 62 kg. dave tosses a 3.7-kg pumpkin to brittany, and when she catches it, she and the skateboard begin to roll backward with a speed of 0.16 m/s.

The maximum restoring force that can be applied to the disk without breaking it is 40000 n. what is the maximum oscillation amplitude that won't rupture the disk