You exert a 100-N force on a pulley system to lift 300 N. What's the mechanical advantage of this system? How many sections of rope support the weight?

Why is combustion of fuel necessary for heat engines to do work?

Two loudspeakers 42.0 m apart and facing each other emit identical 115 Hz sinusoidal sound waves in a room where the sound speed is 345 m/s. Susan is walking along a line between the speakers.

Why is the overall charge on an atom neutral?

A 0.060 kg ball hits the ground with a speed of - 32m/s. The ball is in contact with the ground for 45 milliseconds and the ground exerts a + 55 N force on the ball. What is the magnitude of the velocity after it hits the ground? A. 9.3m/s B.

Which of the following materials is likely to be the best conductor? iron sulfur carbon tin

The kinetic energy of a moving object is equal to the work required to bring it to its speed from rest, or the work the object can do while being brought to rest.

Imagine standing on a bathroom scale and reading your weight. now lift one foot and read your weight again. does the scale read more, less or the same weight when you are standing on one foot?

The period T of a simple pendulum depends on the length L of the pendulum and the acceleration of gravity g (dimensions L/T^2). (a) Find a simple combination of L and g that has the dimensions of time.

What is an example of the theory that the best adapted organisms for an environment are the ones most likely to survive

What does not affect the apparent brightness of a star?