Which statements describe magnetic poles? Check all that apply.

A steam engine takes in superheated steam at 270 °C and discharges condensed steam from its cylinder at 50 °C. The engine has an efficiency of 30%, and taken in 50 kJ from the hot steam per cycle.

Force F1 acts on a particle and does work W1. Force F2 acts simultaneously on the particle and does work W2. The speed of the particle does not change. Which one of the following must be true? a. W1 is zero, and W2 is positiveb. W1 = - W2c.

The force of attraction between two oppositely charged pith balls is 5.3 * 10-6 newtons. If the charge on the two objects is 6.7 * 10-9 coulombs, what is the distance between the two charges? (k = 9.0 * 109 newton·meter2/coulombs2)

Why do you think it is a driving force of weather around the world?

During a snowball fight two balls with masses of 0.4 and 0.6 kg, respectively, are thrown in such a manner that they meet head-on and combine to form a single mass. The magnitude of initial velocity for each is 15 m/s. What is the speed of the 1.

How does the brightness of a bulb tell you about the energy of electrons passing through it?

Why do you think sound travels faster in steel than it does in wood? (Hint: Think about the densities of the two materials, and how the particles might be arranged.)

On which body would a 100kg man have the least gravitational potential energy when lifted to a height of 3 meters

Which of the following factors can negatively affect development? a. Political corruption and instability b. Lack of resources c. Lack of education d. All of the above

A golf ball is hit with an initial velocity of 155 ft/s at an angle of 23 degrees with the horizontal. After 1.4 seconds, how far has the golf ball traveled horizontally and vertically?. a. 199.7 feet horizontally and 75.2 feet vertically. b. 60.