What factors affect friction between two surfaces?

Why does wifi bounce off walls instead of passing through

A 100 kg train traveling at 20 m/s crashes into a stationary 400 kg car. After the collision the car and the train are stuck together. What is their velocity.

Frequency causes us to hear: a. style. b. volume. c. pitch (high and low). d. form. e. i don't know.

1. Find the velocity of a turtle who swims 100 meters toward the shore in 25 seconds.

A baby carriage is sitting at the top of a hill that is 21m high. the carriage with the baby weigh's 12 kg. the carriage has energy. calaculate it

Esulfur burns easily. Iron is attracted by magnets. the mineral made by sulfur and iron, but it does not burn and it is not attracted by magnets. is it a mixture? why? and why not?

What is most likely to be found in both a spinach cell and a muscle cell

Under what conditions might a stream's volume increase, and under what conditions might it decrease? How would the size of the sediment particles in the stream's load differ in the two situations?.

How does the electric force between two charged participles change if one particle's charge is reduced by a factor of 3?

The Wizard of Oz is trying to make a quick escape in his hot air balloon. If the net force on the balloon remains constant, what happens as he throws sand bags out of the balloon's basket? A. The mass of the balloon increases. B.