How does a concave lens differ from a convex lens?

On the moon you would weigh much less than what you weigh on Earth.

A boy on a bus traveling 120 km/h has a foot-long sandwich in his backpack. When the boy gets off at the bus stop, which describes the length of the uneaten sandwich? The length of the sandwich is 1 foot.

How are selective breeding and genetic engineering different? They are not different. Selective breeding involves biotechnology. Genetic engineering involves biotechnology. Both B & C are correct.

What are the cons of using a cup made of ceramic

A freight car moves along a frictionless level railroad track at constant speed. The freight car is open on the top. A large load of sand is suddenly dumped into the freight car.

A student is trying to calculate the density of a ball. She already knows the mass, but she needs to determine the volume as well. Which of the following formulas can be used to calculate the volume of the ball?

Is there such a thing as real time weather radar? why not?

Luke and Carrie are driving down a straight section of the interstate at 70 mph in Luke's new convertible. Carrie is drinking a soda in the passenger seat.

A force produces power p by doing work w in a time t. what power will be produced by a force that does six times as much work in half as much time?

A batter hits a baseball with a bat. The bat exerts a force on the ball. Does the ball exert a force on the bat?