Why is the efficiency of a machine always less than 100 percent

5. Which is not true about a wave in the open ocean? D A Water particles move in a circular path. B As the wave travels, water particles pass the energy along by moving in a circle. O C Water particles travel with the wave.

A chair has a mass of 18g and a density of 150 g/m^3

Why are some animals and plants can become pests when introduced into Australia

Mutt and Jeff are running along a path each pushing a cart loaded with rocks. If Mutt's wagon has a mass two times greater than Jeff's and they want to stay together, arriving at their destination at the same time, what must happen?

What is the average velocity of a car that travels 30 kilometers due wet in 0.50 hour? 0 60 km/hr west O 15 km/hr O 60 km/hr O 15 km/hr west

A projectile is thrown upward so that its distance above the ground after t seconds is h (t) equals negative 16 t squared plus 704 t. a) Find the maximum height the object reaches. b) Find the time it takes the object to reach the ground.

You are standing 100 meters from an object emitting a sound of constant intensity (loudness). You walk toward the source of sound until you are 20 meters from it. From your perspective, what has happened to the intensity of the sound?

What is the peak emf generated by a 0.250 m radius, 500-turn coil is rotated one-fourth of a revolution in 4.17 ms, originally having its plane perpendicular to a uniform magnetic field. (This is 60 rev/s.)

How do credit cards use magnets to work?

Which of the following describes a physical change? A. Formation of a new substance caused by combining substances B. Water changing from liquid to gas through evaporation or boiling C. Formation of a new substance caused by application of heat