John runs for 10 mins at a uniform speed 9kn/h. At what speed should he run for the next 20mins so that theaverage speed comes to 12km/h.

Explain why the speed of a sled increases as it moves down a snow covered hill even though no one is pushing on the sled

What are the principal differences between a radio wave and light? between light and an x-ray?

Determine the deBroglie wavelength for an electron moving at 7.3 x 107 m/sec. A. 1.0 x 10-11 m B. 5.1 x 104 m C. 5.9 x 10-23 m D. 2.9 x 10-7 m

A force does 30000 J of work along a distance of 9.5m. Find the applied force.

One lens of a nearsighted person's eyeglasses has a focal length of - 28.0 cm, and the lens is 1.8 cmfrom the eye.

How many btus of heat energy are needed to raise the temperature of 99.6 lbs of water from 50 °f to 130 °f?

What is a different form of a characteristic, such as brown hair, is called

A book falls of the table and hits the floor. Is work done? Why?

A person of 83 kg is in an elevator. If the elevator is moving at a speed of 5 m/s, what's the person's kinetic energy? Keep 4 significant figures a 1,004 J b 1,038 c 1,280 J d 980 J e 1,435 J

What two equations can be used to determine the speed of a wave