Answer:
36 J
Explanation:
Let's start off with the Kinetic Energy formula: 1/2m
So to find the <em>change</em> in Kinetic Energy, you would first have to find the Kinetic Energy in the beginning and in the end.
*Note: Mass: you incorrectly wrote weight = 6 kg- because weight is a force you have to write 6 Newtons. If you are talking about the <em>mass</em>, you would write 6 kg. If you are talking about weight, you would write 6 Newtons. The difference will make significant changes to the answer, so I will give you the answer for both.
If 6 kg is the MASS:
Beginning: find the kinetic energy.
Plug in all parts of the formula: 1/2mv^2 = (6)(2 squared)=
(6)(4)= 12 J
End: find the kinetic energy.
Plug in all parts of the formula: 1/2mv^2=(6)(4 squared)=
(6)(16)= 48 J
Answer:
36 J
If 6 kg is the WEIGHT:
We know that the weight formula is mg, or mass times acceleration due to gravity (which is always 9.8 m/s^2). Plug in the numbers:
Weight = mass x acceleration due to gravity
6 = mass x 9.8
6 = 9.8m
*Divide both sides*
mass = 0.6 kg
Now, we can use the mass to find the kinetic energy.
Beginning: find the Kinetic Energy
Plug in all parts of the formula: 1/2mv^2 = (0.6)(2 squared)=
(0.6)(4)= 1.2 J
End: find the Kinetic Energy
Plug in all parts of the formula: 1/2mv^2=(0.6)(4 squared)=
(0.6)(16)= 4.8 J
Answer:
3.6 J
(this answer is not very feasible, so 36 J is the way to go. But just remember, don't mix up weight and mass again- as you can see, they lead to different answers!)