Which simple machine is a doorknob?

a lever

a screw

a pulley

a wheel and axle

A thin block of soft wood with a mass of 0.080 kg rests on a horizontal frictionless surface. A bullet with a mass of 4.67 g is fired with a speed of 599 m/s at a block of wood and passes completely through it.

A horizontal 800 N merry go round is a solid disk of radius 1.50 m, started from rest by a constant horizontal force of 50.0 N applied tangentially to the edge of the disk. Find the kinetic energy of the disk after 3.00 s.

What type of plate boundry is located at the mid ocean ridges

What did you notice about crossing two heterozygous genotype?

What best describes why kepler's observation of planetary motion is a law instead of a theory

In a laser, electrical energy is changed to light energy, and a small amount of the energy is wasted as heat. Describe the total amount of the heat in the system (using the conservation of energy).

What is the name for a star and planets held together by gravity? A. solar system B. galaxy C. black hole D. supernova

When a car turns a corner on a level road, which force provides the necessary centripetal acceleration? 1) gravity 2) normal force 3) air resistance 4) tension 5) friction

Use Newton's universal law of gravitation to explain why gravity is greater on Earth than on Mercury.

What is a magnetic field and how does it interact with magnetic materials?