Which describes radioactive decay of a substance

Suppose an object in free fall is dropped from a building. its starting velocity is 0 m/s. whats its speed (in m/s) of the object after falling 2 seconds?

How is water introduced into rivers and streams?

Steam moves into a cylinder of a steam engine at a constant pressure and does 2.34 J of work on a piston. The diameter of the piston is 3.4 cm and the piston travels 4.6cm. What is the pressure of the steam?

Two carts on an air track have the same mass and speed and are traveling towards each other. If they collide and stick together, find (a) the total momentum and (b) total kinetic energy of the system.

A pair of scissors is a complex machine. What are the simple machines you need, to make a pair of scissors?

A machine does 1,500 joules of work in 30 seconds. What is the power of this machine?

A boy standing on the deck of a bridge sees a motorboat approaching in the water below at a constant rate of speed. When the boat is 27 meters from the bridge, the big drops a stone to the water below. If the stone strikes the water 3.

Which object has a varying speed? A. a bird flying 10 m/s for 10 seconds B. a car slowing from 60 m/s for 10 seconds C. a fish moving at 2 m/s for 5 minutes D. a car traveling the speed limit

Most of the energy used by light on earth comes from

If a psychologist were to run an experiment measuring the effects of temperature on aggression the differing temperature would be considered the A. dependent variable. B. experimental variable. C. independent variable. D. random assignmen