The primary mirror in a reflecting telescope is a

plane mirror.

concave mirror.

convex mirror.

Describe the dynamic equilibrium that exists between the two water tanks at right.

Upon impact, bicycle helmets compress, thus lowering the potentially dangerous acceleration experienced by the head. A new kind of helmet uses an airbag that deploys from a pouch worn around the rider's neck.

If the numbers on the plate are 6.0 cm apart, and the spy satellite is at an altitude of 160 km, what must be the diameter of the camera's aperture? (Assume light with a wavelength of 560 nm.)

The amount of energy in the universe is ... A) changing rapidly B) changing slowly C) barely changing at all D) remaining constant

How can the earths mantle flow by convection if it is a solid?

An airplane flies 58 miles in 5 minutes. What is its average speed in miles per hour?

At t=0 a ball is thrown straight upward from the ground level at speed Vo. At the same instant, a distance D above, a ball is thrown straight downward, also at speed Vo. Where do the balls collide in terms of D, Vo, and g?

How do the individual powers of each of the resistors compared to a total power output of the voltage supply?

Unauthorized access, modification, or use of an electronic device or some element of a computer system is called a) denial-of-service attack. b) spamming. c) hacking. d) hijacking.

Energy enables an object to do work. Work is done when A) no force is put on an object, and the object does not move in any direction. B) a force is put on an object, but the object does not move in any direction.