Why is the work output of any real machine less than the work needed to operate it

The graph shown is a velocity-time graph of an object. What is the acceleration of the object from 6.0 to 10.0 seconds?

light beam is directed parallel to the axis of a hollow cylindrical tube. When the tube contains only air, the light takes 8.72 ns to travel the length of the tube, but when the tube is filled with a transparent jelly, the light takes 1.

A child rolls a ball on a level floor 4.0 m to another child. if the ball makes 10.0 revolutions, what is its diameter?

Wave A has a long fetch. Wave B has a short fetch. Which of the following statements is true? Wave A is more powerful than Wave b. Wave B is more powerful than Wave a. Both waves are equally powerful.

An electron traveling horizontally to the right enters a region where a uniform electric field is directed downward. What is the direction of the electric force exerted on the electron once it has entered the electric field?

What is a unit of mass?

Which is not an era of the Phanerozoic eon

Newton's third law states that when an object exerts a force on another object, the second object exerts an equal but opposite force on the first object. Which of the following shows an example of this? a.

A car is moving 14.4 m/s when it hits the brakes. It slow from 78.8 m, which take 9.92s. It then accelerates at 1.83 m/s 2 for 4.50 s. What is the total displacement?

Select all of the answers that apply. What conditions on Earth are unique from other planets in our solar system?