Carlota does 2000 J of work on a machine. The machine does 500 J of work. What is the efficiency of the machine?

4%

25%

75%

400%

What organisms apart from algae would have needed to be present to remove carbon dioxide from the early atmosphere?

How many atoms make up this molecule: C6H14 A) 1 B) 6 C) 14 D) 20

Where would you expect to find the center of gravity in a plastic ruler

The asteroid belt lies between the orbits of which two planets? A. Earth and Mars B. Mars and Jupiter C. Jupiter and Saturn D. Saturn and Uranus

What do you call the period between two full Moons

Which of the following is an example of convection? A. hot air rising and cooler air falling B. a hot object transferring heat to a cooler one C. a hot oven warming the air around it D. the rays of the Sun warming the earth

A 50,000 kg locomotive is traveling at 10 m/s when its engine and brakes both fail. How far will the locomotive roll before it comes to a stop? Assume the track is level.

A rectangular loop of wire with sides 0.262 and 0.401 m lies in a plane perpendicular to a constant magnetic field (see part a of the drawing). The magnetic field has a magnitude of 0.

In the system you're inspecting the damper motor isn't working, You decide to see if the damper-postion sensor us sending the proper signal to the which then signals the damper motor. A. heating coil B. duckwork c. energy source D. controller

Which of the following statements does not describe the structure of an atom? a. An atom has a small, dense center called the nucleus. b. Inside the nucleus of an atom are protons and electrons. c. Protons are positively charged sub-atomic particles.