Q1. What is the mass of a ball that has a kinetic energy of16 J and it is traveling at 4 m/s? Q2. What is the kinetic energy of a soccer ball which has a mass of 1 kg and is kicked with a velocity of 10 m/s?
Q3.exercise ball is on a table 2 m above the ground. What is the mass of the ball if it has a GPE of 40 ?
Q4.What is the gravitational potential energy (GPE) of a 2 kilogram book that is 20 meter above the ground?

Explanation:

Kinetic Energy has a formula of

and

Potential Energy has a formula of

PE = mgh. The first 2 problems use the KE formula and the next 2 use the PE formula.

Q1. KE = 16 and v = 4 m/s:

and

so

m = 2 kg

Q2. mass = 1 kg and v = 10 m/s:

so

KE = 50 J

Q3. PE = 40, h = 2, g = 9.8:

40 = m(9.8)(2) and

so

m = 2.0 kg

Q4. mass = 2 kg, g = 9.8 m/s/s, h = 20:

PE = 2(9.8)(20) so

PE = 392 J

**I completely disregarded the rules for sig fig's because your numbers were very inexact**

the answer for apex is the lowest