A ball is thrown straight up from the ground with an unknown velocity. It returns to the ground after 4.0seconds. With what velocity did it leave the ground?

An emission spectrum shows : a. Brightly colored lines b. A rainbow of colors merging into each other c. Only red and orange bands d. Only green and blue bands

What kind of motion indicates a system where the net force equals zero? A. only accelerating objects B. only stationary objects C. both accelerating and stationary objects D. only objects moving with a constant positive velocity E.

A 9.0-v battery is connected to a bulb whose resistance is 2.5 ω. part a how many electrons leave the battery per minute?

What is the formula for calculating the efficiency of a heat engine Eficiency = White x 100 Eficiency = T"Tox 100 Ericiency = To-Tex 100 Efficiency = Toth x 100

What is the magnitude of an electric field in which the electric force on a proton is equal in magnitude to its weight? Use 1.67*10-27 kg for the mass of a proton, 1.60*10-19 C for the magnitude of the charge on an electron, and 9.

You are in the lab and are given two rods set up so that the top rod is directly above the bottom one. The two straight rods 50-cm long are separated by a distance of 1.5-mm each with 15 A of current passing through them.

What is the explanation for feather beds being warm

A student wearing frictionless in-line skates on a horizontal surface is pushed by a friend with a constant force of 47 N. How far must the student be pushed, starting from rest, so that her final kinetic energy is 354 J?

Suppose a rocket ship in deep space moves with constant acceleration equal to 9.8 m/s2, which gives the illusion of normal gravity during the flight.

A canoeist on a lake throws a 0.145 kg baseball at 20.0 m/s to a friend in a different canoe. Each canoe with its contents has a mass of 120 kg, and is at rest initially.