When dr. hewitt drops a book and a crumpled piece of paper together from the same height, which one hits the ground first?

A ray of light travels from air to water. Which statement about the angle of incidence, reflection and refraction is true? a.

What is the solar system composed of?

The half-life of cobalt-60 is 5 years. How old is a sample of cobalt-60 if only one-eighth of the original sample is still cobalt-60? 5 years 10 years 15 years 20 years

A machine uses a force of 200 newtons to do 20,000 joules of work in 20 seconds. Find the distance the object moved and the power of the machine.

A skydiver jumps out of a hovering helicopter, so there is no forward velocity. Ignore wind resistance for this exercise. 1. What is the skydiver's acceleration

You measure the magnetic field of a long, current-carrying wire to be B is equal to start fraction 50 times mu naught over pi end fraction at a distance of r = 7.5 cm. How much current is running through the wire?

In any food chain or web, the original source of energy is

Which organisms develop gills from pharyngeal arches and later develop lungs to breathe on land

How much energy (in joules) is required to evaporate 0.0005 kg of liquid ammonia to vapor at the same temperature?

It is 5.5 km from your home to the physics lab. As part of your physical fitness program, you could run that distance at 10 km/h (which uses up energy at the rate of 700 W), or you could walk it leisurely at 3.0 km/h (which uses energy at 290 W).