A mass of 20kg produces a momentum of 300kgm/s. What is the Kinetic energy?
- 3250 Joules.
- 2250 Joules.
- 4500 Joules.
Explanation from PART66Online
Momentum p = mv, so velocity = 300 / 20 = 15 m/s. Kinetic energy is half mass times velocity squared: 0.5 x 20 x 15 x 15 = 2250 Joules. A useful shortcut is KE = p squared divided by 2m = 90000 / 40 = 2250 J.
L
Landesberufsschule Knittelfeld asked · 6 Dec 2018
How is this solution calculated?
Community Comments (2)
A
adam86
8 Mar 2019
Momentum = MV
v= momentum/mass
15
1/2mv^2
= 1/2x20x225
2250 joules
v= momentum/mass
15
1/2mv^2
= 1/2x20x225
2250 joules
L
Landesberufsschule Knittelfeld
14 Mar 2019
Thank you. I missinterpreted the term momentum. Now it´s clear.
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