Calculate how long it takes for a stone falling from a bridge with an average acceleration downward of 9.8m/s^2 to hit the water. The stone starts from rest and hits the water with a velocity of 12.3m/s.

A locomotive is pulling 11 freight cars, each of which is loaded with the same amount of weight. The mass of each freight car (with its load) is 37,000 kg. If the train is accelerating at 0.

A force of 9 N acts on an object on a floor to make it move at 6 m s^-1 what would happen to the object if the force is reduced to 3 N?

If workers are allowed a maximum dose of 5.0 rem in 1 year, how close to the source may they operate, assuming a 35-h work week? Assume that the intensity of radiation falls off as the square of the distance.

How do stars make energy

Use KE=/frac{1}{2}mv^{2} Susan and Hannah are each riding a swing. Susan has a mass of 25 kilograms, and Hannah has a mass of 30 kilograms. Susan's swing moves with a velocity of 10 meters/second, while Hannah's swing moves with a velocity of 8.

How can we describe an atom

What is the volume of a gold nugget that weight 2.20kg. the density of gold is 19g/cm^3 ... ?

Explain how newton's first law of motion can be considered to be a consequence of newton's second law.

Propose a hypothesis for how the position of the ball will affect the amount of its gravitational pull energy

A water-skier is pulled behind a boat by a rope that is at an angle of 13° and has a tension of 490 N. The water-skier has a mass of 49 kg. Draw a free-body diagram showing the forces acting on the skier. (She is being pulled to the right.)