How many protons are in the radioactive isotope 40/19K?

The power needed for a 1000 kg car to climb a 5 degree slope is 20,000 Watts. How long did it take if the distance along the slope is 70 m? You may assume the friction and air resistance is negligible.

A street light is at the top of a 16 ft tall pole. A woman 6 ft tall walks away from the pole with a speed of 4 ft/sec along a straight path. How fast is the tip of her shadow moving along the ground when she is 50 ft from the base of the pole?

What is an explanation that unites the findings of many experiments, and it can be changed when new experimental results need to be explained.

What two properties does all matter share?

A train car with mass m1 = 663 kg is moving to the right with a speed of v1 = 8.8 m/s and collides with a second train car. The two cars latch together during the collision and then move off to the right at vf = 5.3 m/s.

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.

If it has enough kinetic energy, a moleculeat the surface of the Earth can escape the Earth's gravitation. The acceleration of gravity is 9.8 m/s2, and the Boltzmanns' constant is 1.38066*10-23 J/K.