A piston, when positioned at the 4cm mark, traps a volume V of gas inside the pump at 75 degrees Celsius and 100kPa. a.) Calculate the volume V given that the cross sectional area of the piston is 10cm^3.
b.) The end of the pump is sealed and the temperature of the gas decreased to 27 degrees Celsius while the pressure increased by 50kPa.
Calculate the new volume of the gas.

How is coal extracted from mountaintop removal mines? a. dynamite is used to create underground tunnels where miners go to extract the coal. b. dynamite is used to break apart rocks and then draglines are used to remove the broken rock and reach the coal. c. coal in mountaintops is extracted by digging strips in the landscape to reach the coal. d. placer deposits in mountain river bottoms are removed by

Which of the following changes will result in a stronger electromagnet? a. using fewer coils of wire b. using a higher voltage c. using a shorter nail d. using a longer wire

Immediately upon reaching its lowest point, a falling pendulum bob has its greatest amount of energy, which is the initial amount of potential energy. a. heat; less than b. heat; more than c. kinetic; less than d. kinetic; more than