Which of the following is best described as an inclined plane twisted into a spiral?

A.

a pulley

B.

a screw

C.

a wheel and axle

D.

a wedge

Why is combustion of fuel necessary for heat engines to do work?

Why is Hubble's law better than using trigonometric parallax?

A child of mass 48.7 kg sits on the edge of a merry-go-round with radius 3 m and moment of inertia 376.938 kg m^2. The merry-go-round rotates with an angular velocity of 2.5 rad/s.

If a car changes its velocity from 32 km/hr to 54 km/hr in 8.0 seconds, what is its acceleration?

How do I obtain the poon?

The scientific method begins with recognizing a problem. The recognized problem in this scenario is, "Why is the printer in the office not working?" Choose the hypotheses that are testable and from which an experiment can be formed.

The correctly balanced equation for H2O2 → H2O + O2 is

How would an unbalanced chemical equation convey misleading information about what took place during a chemical reaction?

A car rounds a 75-m radius curve at a constant speed of 18 m/s. a ball is suspended by a string from the ceiling the car and moves with the car. the angle between the string and the vertical is:

Emission of light from an atom occurs when an electron