a boy stands 80m in front of a tall cliff and produces sound by clapping two planks together. A girl standing next to him time the return of the echo at 0.5. how fast does sound wave travel in this place

In the 25-ft Space Simulator facility at NASA's Jet Propulsion Laboratory, a bank of overhead arc lamps can produce light of intensity 2500W/m2 at the floor of the facility. (This simulates the intensity of sunlight near the planet Venus.

A piston-cylinder device contains 3 kg of saturated water vapor at 200 kPa. Now heat is transferred to the system at constant pressure until the temperature reaches 200oC. Calculate the work done by the steam during this process.

Group 18 noble gases are inert because a. they readily form positive ions. b. they can have either a positive or a negative charge. c. their outermost energy level is missing one electron. d. their outermost energy level is full.

In order to be sure a grinder used in production is operating properly, what feature of the grinder should be checked daily?

12) Does the label "centripetal force" ever appear in an FBD?

A mover hoists a 200 kg piano from the ground to a height of 10 m using a single pulley. What was the change in the pianos energy? a. 20j b. 200j c. 2000j d. 20000

When you hear sound pulses (beats), describe how you will determine the beat frequency. Include in your answer what steps you will take to reduce percentage uncertainty, as well as how you will turn raw measurements into your final answer.

An elevator has mass 600 kg, not including passengers. the elevator is designed to ascend, at constant speed, a vertical distance of 20.0 m (five floors) in 16.0 s, and it is driven by a motor that can provide up to 40 hp to the elevator.

Suppose that 100g of aluminum at 23 degrees C is added to 50g of water at 95 degrees C. Determine the equilibrium temperature of the mixture. Ignore heat loss to the container or the surroundings.

Which property of coal makes it ideal for use in a power plant? Check all that apply. It burns easily. It makes ash. It is renewable. It produces a lot of energy. It contains mercury.