N any ecosystem, the size of a population A. always stays the same. B. only depends on the population's reproductive rate. C. only depends on the amount of resources available. D. may change over time.

A railroad car of mass 2.30e+4 kg moving with a speed of 3.00 m/s collides and couples with two other coupled railroad cars each of the same mass that are already moving in the same direction at a speed of 1.10 m/s.

A package falls from an airplane in level flight at constant speed. If air resistance can be neglected, how does the motion of the package look to the pilot

At the same velocity, which object will have the greater momentum a 1000 kg compact car a 5000 kg pick up truck a 50 kg bicycle a 70 kg man

How much power is produced by a flashlight that has a voltage of 12 volts and a current of 6.5 * 10-2 amps? 0.78 watts 78 watts 190 watts 0.0054 watts 1.9 watts

A pile driver lifts a 450 kg weight and then lets it fall onto the end of a steel pipe that needs to be driven into the ground. A fall of 1.5 m drives the pipe in 45 cm. What is the average force exerted on the pipe?

Which condition is a neuron in when the outside of the neuron has a net positive charge and the inside has a net negative charge?. Threshold. Action potential. Resting potential

Use combustion by moving pistons which respond to a change in pressure

If q1 is 2μC, q2 is 5μC and r1 = 0.2m, then the force between the charges is

On a weather map places that have the same temperature are joined with lines called

Which of the following generally speed up a reaction? A. increasing the activation energy B. removing any catalysts C. adding more heat D. shaking the container holding the reaction