A skater spins with a roatation of 3 cycles per second. If she draws in her arms so that rotational inertia is reduced to 80% of her former amount, what will be her spin rate?

150 g of liquid nitrogen at its boiling point of 77.0 K is stirred into a beaker containing 510 g of 18.0°C water. If the nitrogen leaves the solution as soon as it turns to gas, how much water freezes? The heat of vaporization of nitrogen is 48.0 cal/g and that of water is 80.0 cal/g

a. none b. 21 g c. 42 g d. 11 g e. 63 g

A container is filled with water and the pressure at the container bottom is P. If the container is instead filled with oil having specific gravity 0.80, what new bottom pressure results?

a. a pressure < P b. the same pressure P c. a pressure > P d. This is unable to be determined with the information given.

When you look at a single slit diffraction pattern produced on a screen by light of a single wavelength, you see a bright central maximum and a number of maxima on either side, their intensity decreasing with distance from the central maximum. If the width of the slit is increased,

a. the pattern shrinks in size. (central maximum less wide; other maxima in closer to it) b. the pattern increases in size. (central maximum wider; other maxima farther from it) c. it does not affect the size of the pattern. d. the width of the central maximum increases, but the other maxima do not change in position or width. e. the width of the central maximum decreases, but the other maxima do not change in position or width.

On a scale where the Sun is about the size of a grapefruit and the Earth is about 15 meters away, how far away are the nearest stars besides the Sun?

A) 100 meters B) about the distance across 50 football fields C) about the distance across the state of Delaware D) about the distance across the United States