When a 100-ω resistor is connected across the terminals of a battery of emf ε and internal resistance r, the battery delivers 0.794 w of power to the 100-ω resistor. when the 100-ω resistor is replaced by a 200-ω resistor, the battery delivers 0.401 w of power to the 200-ω resistor. what are the emf and internal resistance of the battery? (a) ε = 10.0 v, r = 5.02 ω(b) ε = 12.0 v, r = 6.00 ω(c) ε = 4.50 v, r = 4.00 ω(d) ε = 9.00 v, r = 2.04 ω(e) ε = 9.00 v, r = 1.01 ω

Because air contracts as it cools, the air pressure inside a freezer is typically lower than on the outside. why do ice cubes inside a freezer tend to shrink over time? a. the ice dissolves oxygen from the air, forming a denser crystalline matrix. b. the ice reacts chemically with carbon dioxide in the air, forming gaseous carbon compounds. c. the ice melts, and then the liquid freezes as ice crystals on the bottom of the freezer. d. the ice sublimes, and then the water vapor deposits as ice crystals on the sides of the freezer.

Two carts, one of mass 2m and one of mass m, approach each other with the same speed, v. when the carts collide, they hook together. assume that positive momentum is to the right. which graph best represents the momentum of both carts over time, before and after the collision?

Mechanical energy is when the amount of kinetic and potential energies added together remains the same. conserved created lost