Assume that a machine puts out 8000 joules of work when the user puts in 10,000 joules of work. What is the efficiency of the machine?

A turtle, moving at a constant velocity of 0.9 m/s due East, is in a race with a rabbit, who runs at a moderate speed of 9 m/s.

A cooling tower for a nuclear reactor is to be constructed in the shape of a hyperboloid of one sheet. The diameter at the base is 260 m and the minimum diameter, 500 m above the base, is 220 m. Find an equation for the tower.

If it takes 100 N to move a box 5 meters, what is the work done on the box? A. 500 J B. 20 J C. 5 J D. 5,000 J

What are the units for velocity and acceleration

Tina and her puppy are tugging on a rope each pulling on opposite ends when is tina doing work? When is Tina doing work?

Kim holds a pinwheel in the air and says it can be used to model a source of energy. Identify the type of energy Kim's pinwheel models. Explain the type of energy source used.

An example of a stable system

What causes chemical weathering? a. damage caused by animals and plants c. natural acids b. ice wedging d. physical factors

1. Strzała o masie 20 g tuż po wystrzale ma prędkość 50 m/s. Oblicz pracę wykonaną przez zawodniczkę. Ile wynosi energia potencjalna sprężystości napiętej cięciwy? 2. Na trampolinę o współczynniku sprężystości k=2 kN/m stanął zawodnik o masie 80 kg.

Two small plastic spheres between them has magnitude 0.22 N. What is the charge on each sphere is one the other? Explain whether it can be determined from the information give, whether the charges are positive or negative.