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.

which best describes lenny’s error?

in step 1, he should have found the square root of 400 j instead of squaring 8 m/s.
in step 1, he should have multiplied 8 m/s by 2 instead of squaring it.
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/s2 by 2 instead of dividing it by 2.