Which of these gases, when mixed with moisture in the atmosphere, can form acid rain
a. oxygen
b. nitrogen
c. hydrogen
d. sulfur dioxide

As you are trying to move a heavy box of mass m, you realize that it is too heavy for you to lift by yourself. there is no one around to , so you attach an ideal pulley to the box and a massless rope to the ceiling, which you wrap around the pulley. you pull up on the rope to lift the box. use g for the magnitude of the acceleration due to gravity and neglect friction forces. once you have pulled hard enough to start the box moving upward, what is the magnitude f of the upward force you must apply to the rope to start raising the box with constant velocity? express the magnitude of the force in terms of m, the mass of the box.

The electric field inside a battery generates an electric potential difference of 12v. the plates are seperated by a distance of 0.25m. what strength of the electric field?

If a 250-g mass is hung on two identical springs, hung side by side , and both support the 250-g mass, how much will each spring stretch?