# Linear Momentum question – Plz help!!

**1. The problem statement, all variables and given/known data**

A 15,000 kg loader traveling east at 20 km/h turns south and travels at 25 km/h. Calculate the change in the loaders

kinetic energy.

linear momentum.

**2. Relevant equations**

KE2-KE1 = change in KE

p=mv

**3. The attempt at a solution**

a.

20km/hr = 5.56m/s

25km/hr=6.94 m/s

KE2-KE1

1/2mv2^2 – 1/2mv1^2

1/2 (15000)(6.94)^2 – 1/2(15000)(5.56)^2

361227-231852

129375J

b. p(east) = mv1

(15000)(5.56)

83400

p(south) = mv2

(15000)(6.94)

104100

using pythagorean theorem for the two sides I know I got 133388 kg m/s for the magnitude of the momentum..

Am I doing this right??? I also don’t know if I can just use p(east) and p(south) to find the angle of the momentum – does 83400/104100 = 0.801152737 then inv cos – 36.8 degrees work? Doesn’t sound right to me
Or can I just show the direction using N/E/S/W

http://ift.tt/1hH8ANz

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