if you have to apply 40 N of force on a crowbar to lift a rock that weighs 400 N, what is the actual mechanical advantage of the crowbar?

What is the equation that relate electric potential (voltage) to electric field?

Which element above has 15 protons in its nucleus? A. oxygen B. carbon C. phosphorus D. sulfur

What forces cause plate movement

The segment is shrunk to one-third of its original length. What is the ratio λf/λiλf/λi, where λiλi and λfλf are the initial and final linear charge densities?

Donna is trying to make an electromagnet to pick up old nails around her driveway. Which of these materials would be best to use for the core in order to make the strongest electromagnet to pick up the most nails?

A submarine that is in the sea what principle is that

1. It takes 26.5 N to pull a 72 kg sled across snow. What is the coefficient of friction? 2. A 565 N rightward force pulls a large box across the floor with a constant velocity of 0.75 m/s. If the coefficient of friction is 0.

A person holds onto an object for 2 minutes, but doesn't move the object. Is work done on the object?

Which two vectors add together to give a resultant with the smallest magnitude, and which two vectors add to give a resultant with the largest magnitude? in each case specify the magnitude and direction of the resultant?

The largest velocity reached by a falling object is its