Which simple machine is a doorknob?

a lever

a screw

a pulley

a wheel and axle

Which of the following is true about grasslands? a. They have numerous trees. b. They have a large number of tree-dwelling birds. c. They experience a wide temperature range over two seasons. d. They have four distinct seasons.

What causes light traveling in a straight line to bend? A traveling through a dense liquid B moving toward a solid object C traveling through a uniform medium D moving through the boundary of a new medium

The way a rock reflects light is called the rock's A. streak O B. luster O C. cleavage D. specific gravity

Watt which is a unit of power is equal to

N which one of the following locations can a person hear the echo of a sound?

The vapor pressure of ethanol at 25 degrees C is 7.83 kPa. Calculate the vapor pressure in atm. Round answer to 3 significant digits.

According to Newton's second law of motion acceleration or an object depends upon the ___ of the object and the ___ Acting on it. I'm confused on what the blanks are. I can't find them.

What is the concentration of H + ions at a pH = 7?

Suppose that Paul D. Trigger fires a bullet from a gun. Will the speed of the bullet leaving the muzzle will be the same as the speed of the recoiling gun? Explain.

A certain rock contains large jagged pieces of other rocks cemented by fine particles what type of rock is this explain