Elevators lift loads by employing a motor and a complex system of pulleys. If the elevator converts all the energy used to work (no heat or friction is generated), how many Joules would be required to lift a 2,500 N load 15 m?​

Which is an example of gaining a static charge by conduction? a) rubbing a balloon against your hair. b) shuffling your shoes across a carpet. c) bringing a charged rod near an electroscope. d) touching your car on a cold day and getting a shock.

Which of the following are considered noble gases? a. bromine b. neon c. argon d. chlorine

An important dimensionless parameter concerned with very high-speed flow is the mach number, defined as v/c, where v is the speed of the object such as an airplane or projectile, and c is the speed of sound in the fluid surrounding the object. for a projectile traveling at 1170 mph through air at 50 ˚f and standard atmospheric pressure, what is the value of the mach number?