Which of these are not mechanical waves and can be used to send a signal to astronauts on the moon?

A) sound waves

B) radio waves

C) both sound waves and radio waves

D) neither sound waves or radio waves

Pressure is dependent on how much force is exerted in what amount of area. t or f

The kinetic energy of the air molecules inside the cave is the kinetic energy of the air molecules outside the cave.

A refrigerator is used to cool water (Cp = 4.18 kJ / (kg. oC) & density  = 1 kg/L) from 23 oC to 5 oC in a continuous manner. The heat rejected in the condenser is 570 kJ/min and the power of the compressor is 2.65 kW.

Which of the following is NOT an important positive motivating factor for those considering exercise? a. building strength, endurance, and energy b. reducing time commitments to family c. improvement of health and performance d.

A satellite moves around the Earth in a circular orbit of radius r. What is the speed vi of the satellite?

The force of attraction between two oppositely charged pith balls is 5.3 * 10-6 newtons. If the charge on the two objects is 6.7 * 10-9 coulombs, what is the distance between the two charges? (k = 9.0 * 109 newton·meter2/coulombs2)

To describe velocity you need to know?

Mohammed made a chart to list examples and nonexamples of projectile motion. Which best completes the chart? a - a football thrown in the airb - a kite flying on a stringc - a golf ball rolling off a table d - water spraying from a fountain

Halley's Comet appears around the sun about once every 76 years. It passes through the part of its orbit nearest the sun in just a few months but then moves out to great distances and takes more than half a century for the rest of its orbit.

In order to hike around a portion of Lake Allatoona, a tour guide determines that he must take his group 150 m east, 60 m north, then 75 m west.