Which simple machine is a doorknob?

a lever

a screw

a pulley

a wheel and axle

Which type of air mass originates in the Gulf of Mexico?

A student standing on the ground next to a tall building throws a ball straight up with a speed of 39.2 m/s. If it takes the ball 4 seconds to reach the same height as the top of the building, how tall is the building?

Original water slide tornado ride names I need this for science not things that exist already anyone have names for water slides that look like tornados?

What can scientist learn from studying sedimentary rocks?

If a force of 19 N is applied to a crate to push it 23 m, how much work is done on the crate by the force?

Calculate mass During a softball game a softball is struck by a bat and has an acceleration of 1,500 kg. If the net force force exerted on the softball by the bat is 300 N, what is the softballs mass.

Find the momentum of a 25 kg remote controlled car moving 4.0 m/s (Type your answer below, don't forget your significant figures and units!)

When a wave slows down it ... a. bends away from the normal b. bends towards the normal c. continues in a straight line

Select the statement that best describes how the forces relate. A. The object on which they are acting and the distance to that object determines the amount of force. B.

A block with m = 300 grams oscillates at the end of a linear spring with k = 6.5 N/m. (assume this is a top-down view and the block is sliding on a frinctionless surface;