A tennis ball (m=0.2 kg) is thrown at a brick wall. it is traveling horizontally at 18 m/s just before hitting the wall and rebounds the wall at 12 m/s, still traveling horizontally. the ball is in contact with the wall for 0.02 s. what is the magnitude of the average force of the wall on the ball

He latent heat of vaporization for ethyl alcohol is 854 j/g. the amount of energy, rounded to the nearest whole number, needed to change 5.20 grams of ethyl alcohol from a liquid to a gas is

Asynthetic fiber used in manufacturing carpet has tensile strength that is normally distributed with mean 75.5 psi and standard deviation 3.5 psi. how is the standard deviation of the sample mean changed when the sample size is increased from n equals 8 to n equals 47

Astudent in a science lab is investigating heat transfer and thermal energy conservation as she mixes hot and cold water.she first measures out her desired amount of cold water into a styrofoam cup. she then measures out hot water from the faucet or from a pot hot water on her stove. after she measures the temperature of the hot and cold waters, she pours the hot water into the cold water. she monitors the temperature of the mixed waters and records the final temperature. she uses a standard thermometer to record the temperatures. she does three trials, which are shown below: