What are earthquakes usually associated with?

If pie trays are stacked on top of a Van de Graaff they will fly into the air one after another. Why does this happen?

A car is travelling down a straight road. The driver presses on the accelerator but the car does not change speed. How is this possible?

A 7.12 μC charge is moving at the speed of light in a magnetic field of 4.02 mT. What is the force on the charge?

A 26-g steel-jacketed bullet is fired with a velocity of 630 m/s toward a steel plate and ricochets along path CD with a velocity 500 m/s.

A 50.0-kg block is being pulled up a 15.0° slope by a force of 250 n which is parallel to the slope. the coefficient of kinetic friction between the block and the slope is 0.200. what is the magnitude of the acceleration of the block?

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.