When galaxies move away from us they appear to have a "red shift" in color. Explain why this happens.

Wich is a scalar quantity (1) velocity (2) speed (3) acceleration (4) displacement

What are some of the obstacles to exploration of outer planets or even Venus right next door? distance cost enough supplies and equipment for the trip all of the above coping with the extreme atmospheres

How much work is being done if a force of 75 Newtons is used to push a box a distance of 100 meters?

A 400-kg stopped at an intersection is rear-ended by a 1600-kg truck moving at 10 m/s. If the car was in neutral and the brakes were off, so that the collision is approximately elastic, find final velocity of the car if the truck was moving 5 m/s

A thread holds a 1.5-kg and a 4.50-kg cart together. After the thread is burned, a compressed spring pushes the carts apart, giving the 1.5 kg cart a speed of 26 cm/s to the left. What is the velocity of the 4.5-kg cart? a. 10 cm/s b. 4.56 cm/s c. 8.

What causes day and night on earth?

A yo-yo can be thought of as a solid cylinder of mass m and radius r that has a light string wrapped around its circumference (see below). One end of the string is held fixed in space.

Why is time an independent variable and position is a dependent variable in a position versus time graph

A geologist estimates that a large boulder weighs 7840 N. What should he estimate the mass of this boulder to be? A. 650 kg B. 740 kg C. 780 kg D. 800 kg

Two objects have the same momentum. Do the velocities of these objects necessarily have (a) the same directions and (b) the same magnitudes? Give your reasoning in each case.