Which type of wave can travel without a medium

Which will speed up a chemical reaction? Apply heat. Increase the concentration of the reactants. Grind up the substance, so there is more surface area. all of the above

What are elements made of?

1. How does potential energy differ from kinetic energy?

Two children with masses of 20 and 30 kg are sitting on a balanced seesaw. if the lighter child is sitting 3 m from the center, how far from the center is the heavier child sitting?

A motorist makes a trip of 180 miles. For the first 90 miles she drives at a constant speed of 30 mph at what constant speed must she drive the remaining distance if her average speed for the total trip is to be 40 mph

Which electromagnetic wave has the shortest wavelength? (A. Radio waves b. X-rays c. infrared rays or d. Visible light)

If blue light hits a red filter, what kind of light comes through the filter? a. red b. blue c. purple d. no light

The tip of a triangle is held 12.0 cm above the surface of a flat pool of water. A submerged swimmer in the pool sees the tip of the triangle at what distance above the water? Let the indices of refraction nwater = 1.33 and nair = 1.00.

Which one of the graphs below also corresponds to a historical form of record keeping? bar graph pictograph line graph pie chart

A 4-W night-light is plugged into a 120-V circuit and oper - ates continuously for 1 year. Find the following: (a) the current it draws, (b) the resistance of its filament, (c) the energy consumed in a year.