A grenade of mass 10 kg explodes into three pieces in the same plane, two of which, A (5.0 kg) and B (2.0 kg), move off as shown. Calculate the velocity of the 3.0 kg third piece, C.(adsbygoogle = window.adsbygoogle || []).push({});

I cannot show all of my work becuz it is basically just a sketch of what the diagram would look like, then drawing vectors and so on. However, i cannot get the right answer.

So heres the diagram it shows...

http://www.cbv.ns.ca/rv/physics/Physics12/BLM10-3.pdf

Δp = 0 where pi = 0

pix = pfx and piy = pfy

p1’

p1y’ = Cos30(5.0 kg (100.0 m/s))

= 433.013 kgm/s

p1x’ = Sin30(5.0(100m/s))

= 250

p2y’ = cos20 (2kg)(200 m/s)

= cos20 ( 400 kgm/s)

p2x’ = sin20 (400 kgm/s)

p1x’ + p2x’ + p3x’ = 0

500 + (- sin 20 (400 kgm/s)) + p3x’ = 0

p3x’ = 363.192 kgm/s

p1y’ + p2y’ + p3y’ = 0

500 kgm/s + (- cos 20(400 kgm/s)) + p3y’ = 0

p3y’ = 124.123kgm/s

p3 is found by resolving p3x’ and p3y’

p3x’

p3y’

p3

θ

p3^2 = [363.192kgm/s]2

+[124.123 kgm/s]2

|p3| = 383.816 kgm/s

θ = tan-1 [(124.123kgm/s)/(363.192kgm/s)]

= 19 degrees? wtf v3 = p3/m3

v3 = 383.816kgm/s/(3kg)

v3 = 128 m/s

This is completely wrong the answer is suppose to be V3= 128.92 m/s (S 82 E) or something....soo where did i go wrong? and is there an easier wayyyyy!!??

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Impulse and Momentum Problem!

**Physics Forums | Science Articles, Homework Help, Discussion**