In what sense are telescopes like time machines?

Explain the advantages and disadvantages of using concentric circles in describing the solar system to an elementary school child.

A baseball player comes to a stop as he slides into a base. Which two things slow him down as he slides?

A long, slender structural steel [E = 29,000 ksi] HSS8 x 4 x 1/4 shape (see Appendix B for its cross-sectional properties) is used as a L = 43.50-ft-long column.

find the final speed and the time taken for a skier who skies 75 m along a slope that is 15°, measured from horizontal, in the following situations (you may neglect friction).

You and your friends are going to play laser tag. This game is played in a dimly lit room where you shine lasers in an attempt to tag your opponent. What color of shirt would be the most advantageous shirt to wear and why?

What is the efficiency of a machine that has work input of 40 joules and work output of 35 joules

What happens to an object if the forces acting on it are unbalanced?

A 92-kg astronaut and a 2000-kg satellite are at rest relative to a space station. the astronaut pushes on the satellite, giving it a speed of 0.14 m/s directly away from the station.

How to calculate wavelength in m when you know the frequency?

Ball A has a mass of 0.200 kilograms. Ball A, traveling at a velocity of 2 meters/second in the + x direction, hits a stationary ball B of the same mass. After the collision, ball B bounces off at a positive angle with respect to the + x-direction.