Compare and contrast natural elements and synthetic elements

Effieciency of a machine is never 100%

Describe how the size of the force of friction depends on the size of the normal force?

When a rock is held above the ground, we say it has some potential energy. When we let it go, it falls and we say the potential energy is converted to kinetic energy. Finally, the rock hits the ground (and stays there).

One of the most efficient engines built so far has the following characteristics: combustion chamber temperature = 1900°C, exhaust temperature = 430°C, 7.0 * 109 cal of fuel produces 1.4 * 1010 J of work in one hour.

Most asteroids are found between the orbits of neptune and uranus ture or false

Why are convection currents; why are they hotter and colder parts of earth

A swimmer is swimming to the left with a speed of 1.0 m/s when she starts to speed up with constant acceleration. The swimmer reaches a final speed of 2.5 m/s over a distance of 5.0 m. How long did the swimmer take to speed up to 2.

An archer defending a castle is on a 15.5 m high wall. He shoots an arrow straight down at 22.8 m/s. How much time does it take to reach the ground?

Four potential forces can act on the ball Which combination of forces will keep the ball in static equilibrium? The length of the arrows represents the magnitude of the force A and B A and C B and D 8. Cand D Submit Force, Mass, and Motion

The resultant of a 50N force acting on an object to the right and a 20N force acting on the object to the left is what