Which best describes Lenny's error? Lenny wrote the steps he used to find the mass of an
object with 400 J of energy moving at a velocity of 8
m/s.
1. Find the square of 8 m/s, which is 64 m²/s2.
2. Divide kinetic energy, 400 J, by 64 m²/s2, which is
6.25 J per m²/s2
3. Divide 6.25 J per m²/s2 by 2 to get a mass of 3.125
kg.
O In Step 1, he should have found the square root of
400 J instead of squaring 8 m/s.
O In Step 1, he should have multiplied 8 m/s by 2
instead of squaring it.
O In Step 2, he should have divided 64 m2/s2 by 400 J
instead of dividing 400 J by 64 m2/s2.
In Step 3, he should have multiplied 6.25 J per m²/s?
by 2 instead of dividing it by 2.

Trumpeter a holds a b-flat note on the trumpet for a long time. person c is running towards the trumpeter at a constant velocity. person b is running away from the trumpeter at the same rate. person d is standing still the whole time. which person hears a frequency that is lower than the b-flat?

1point) a skydiver weighing 130 lb (including equipment) falls vertically downward from an altitude of 14,000 ft and opens the parachute after 20 s of free fall. assume that the force of air resistance, which is directed opposite to the velocity, is of magnitude 0.85|v|0.85|v| when the parachute is closed and is of magnitude 17|v|17|v| when the parachute is open, where the velocity vv is measured in ft/s. assume that acceleration due to gravity has magnitude 32 ft/s/s; remember that weight is the product of mass and gravitational acceleration. find the speed of the skydiver when the parachute opens. speed is 150.6121788 ft/s find the skydiver's height when the parachute opens. height is 2338.98591 ft find the limiting velocity vlvl after the parachute opens. (think about whether this should be positive or negative.) vl=vl= 7.647 ft/s

Which of the following are forms of phase changes a. freezing b. condensation c. heating d. exchanging