FREE POINTS FOR EASY QUESTION An experimenter completes an experiment on which is the best light bulbs to use in a certain type of lamp. He tries 4 different light bulbs in the same lamp. He turns the lamp on with each type of light bulb for the same amount of time.

What is the manipulated variable in this experiment?

the amount of time the lamp is on

the lamp

the light bulbs

the amount of energy used

If we relied solely on the nonrenewable resources found in the u.s., which one would we run out of first at current usage levels? a. natural gas b. oil c. uranium d. coal

Two pans of a balance are 24.1 cm apart. the fulcrum of the balance has been shifted 1.33 cm away from the center by a dishonest shopkeeper. by what percentage is the true weight of the goods being marked up by the shopkeeper? assume the balance has negligible mass. answer in units of %.

Four point charges each having charge q are located at the corners of a square having sides of length a. find symbolic expressions for the following. (a) the total electric potential at the center of the square due to the four charges (use any variable or symbol stated above along with the following as necessary: ke.) vtotal= (b) the work required to bring a fifth charge p from infinity to the center of the square (use any variable or symbol stated above along with the following as necessary: w=