A baseball was hit at 45 m/s at an angle of 45 degrees above the horizontal. A.) how long did it remain in the air?
B.) how far did it travel horizontally?

Answer: it will take   4.36 seconds to reach her average velocity 10.69 miles/hour.explanation:   we have equation of motion ,where s is the displacement, a is the acceleration, u is the initial velocity and t is the time taken.average velocity = displacement/ time taken.average velocity = 10.69 miles/hr = 10.69*1.6*1000/(60*60) = 4.75 m/s4.75 = s/ts = 4. 1we also have acceleration = 2.18 m/s², initial velocity = 0 m/sso it will take   4.36 seconds to reach her average velocity 10.69 miles/hour.

The density of the block of iron is lees than the density of mercury but the density of the block of iron is greater than the density of water

Repeated trials allow you to calculate a mean which can reduce the effect of random errors to make your results more precise.your results will also be reproducible therefore if someone else did the same experiment they'd get the same results which would make your results more reliable.