Head restraints can reduce the risk of injury by reducing the differential motion of an occupant�s head and torso in a rear end crash.

Which statement is true? a. kepler's laws apply only to the motion of earth. b. kepler's laws can be used to predict eclipses. c. kepler's laws are true for a central force that is directly proportional to distance. d. kepler's laws can be deduced from newton's laws of motion and gravity.

Astudent pushes on a 20.0 kg box with a force of 50 n at an angle of 30° below the horizontal. the box accelerates at a rate of 0.5 m/s2 across a horizontal floor. what is the value of the normal force on the box? 200 n 243 n 156 n 225 n

At very high pressures, gases become and will eventually a) more dense; become hotter b) more dense; change to a liquid or solid c) less dense; combust d) less dense; turn into a liquid