Why gaps are left between rails while laying railway tracks

a block of wood is found to have dimensions of 6.21 cm x 4.63 cm x 5.34 cm. Calculate the volume of the block

A 700 kg racecar slowed from 30 m/s to 15 m/s. What is the change in momentum

Uranus is most similar in size and composition to A) Mars B) Earth C) Jupiter D) Neptune

Direct current made it possible to distribute electric power over greater areas. a. True b. False

A model rocket engine has an average thrust of 5.26 n. it has an initial mass of 25.3 g, which includes fuel mass of 12.8 g. the duration of its burn is 1.90 s. (assume all the fuel is consumed.) (a) what is the average exhaust speed of the engine?

The national grid supplied a house with 18000000 J of energy in 1 hour. What was the average current supplied to the house in that hour? Write any equations that you use.

Claudia throws a baseball to her dog. Which free-body diagram shows the baseball when it's flying horizontally in midair? (Assume no air resistance.)

Which of the following substances will show the smallest change in temperature when equal amounts of energy are absorbed? water air sand concrete

The downward acceleration of a falling body on Earth is 9.81m/s2. On the moon the same quantity is 1.62m/s2. An astronaut in a space suit has a mass of 145kg.

Explain how a guitar produces sound by using the terms standing waves and resonance.