use Archimedes’ principle to calculate the volume (in m3) of helium needed if a helium balloon is to lift a load of 161 kg? (NB: Ignore the weight of the balloon; take the mass density of air and helium as 1.737 kg/m3 and 0.11kg/m3 respectively.)

If jill was traveling at 300 miles in 4 hours due south what was his velocity in miles per minute a) 75 miles per hour due south b) .02 miles per second due south c) .5 miles per second due south d) 1 mile per hour due south

Arunner is jogging at a steady 3.6 km/hr. when the runner is 2.9 km from the finish line, a bird begins flying from the runner to the finish line at 14.4 km/hr (4 times as fast as the runner). when the bird reaches the finish line, it turns around and flies back to the runner. even though the bird is a dodo, we will assume that it occupies only one point in space, i.e., a zero-length bird. how far does the bird travel? (b) after this first encounter, the bird then turns around and flies from the runner back to the finish line, turns around again and flies back to the runner. the bird repeats the back and forth trips until the runner reaches the finish line. how far does the bird travel from the beginning? (i.e. include the distance traveled to the first encounter)

Which of the following is the main energy source for the sun? a. fission of hydrogen b. fusion of hydrogen c. fusion of helium d. fission of iron