A weight lifter bench‑presses a 150.0 kg 150.0 kg barbell from his chest to a height equal the length of his arms, 0.850 m. 0.850 m. How much work does he do?

Which of the following is true about density and states of matter for most substances? A substance is denser as a solid than as a gas. B substance is denser as a liquid than as a solid. C substance is denser as a gas than as a liquid.

How are molecules in a neutral state different from ions?

A machine supply energy at a rate of 4000 W and does used to work at a rate of 3760 W what is the efficiency of the machine?

A boat has a mass of 4040 kg. Its engines generate a drive force of 4660 N due west, while the wind exerts a force of 880 N due east and the water exerts a resistive force of 1400 N due east. Take west to be the positive direction.

1. x-rays of wavelength 0.138nm fall on a crystal whose atoms, lying in planes, are spaced 0.285 nm apart. At what angle with the surface must the x-rays be directed if the a. first diffraction maximum is observed? b.

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.