What is the efficiency of a machine that miraculously converts all the input energy to useful output energy?

According to Galileo's pendulum theory, which factor determines the time taken to swing through one complete cycle?

A stone is dropped off a cliff in 3.55s how high is the cliff?

The current passing through a room heater has been halved. what will happen to the heat produced by it?

A commuter train blows its 200-Hz horn as it approaches a crossing. The speed of sound is 335 m/s. An observer waiting at the crossing receives a frequency of 207 Hz. What is the speed of the train?

Which of the following is a characteristic of analog data? - It is converted into numbers for transmission - It is converted into numbers for storage - It can travel as a square wave - It is easily lost or hidden by noise

For a stationary observer, when the source of a sound is moving, its pitch appears to change.

Give an example of each simple machine

The product PV, where P and V represent pressure and volume respectively, is a unit for which? A entropy B force C impulse D work

IF it possible for an object to move for 10 seconds at a high speed and end up with an average velocity of zero? true or false

The boy moving down the hill posses what energy?