A boy whirls a ball on a string in a horizontal circle of radius 0.6 m. If the ball is traveling at 9 m/s, what is the centripetal acceleration? a)135 m/s2
b)62.5 m/s2
c)72 m/s2
d)90 m/s2
e)24 m/s2

Which safety measures should you follow during a thunderstorm? check all that apply. (a) avoid touching anything that conducts electricity. (b) avoid touching a person who has been struck by lightning. (c) go outside. (d) keep your computer turned off. (e) stay out of water. (f) stay inside.

At an oceanside nuclear power plant, seawater is used as part of the cooling system. this raises the temperature of the water that is discharged back into the ocean. the amount that the water temperature is raised has a uniform distribution over the interval from 10° to 25° c. what is the standard deviation of the temperature increase?

If you put a helium-filled balloon in the refrigerator, what will happen?