I can solve this problem, but I keep getting a different answer from the textbook. I just want to confirm whether I'm wrong or the textbook is wrong.
A truck of mass 2.3 x 104 kg travelling at 15 m/s [51° S of W] collides with a second truck of mass 1.2 x 104 kg. The collision is completely inelastic. The trucks have a common velocity of 11 m/s [35° S of W] after the collision.
Determine the initial velocity of the less massive truck.
v`(m1 + m2) = v1m1 + v2m2
The Attempt at a Solution
P22 = 3850002 +3450002 -2(385000)(345000)cos16°
P2 = 109045
V = P2 / m2
V = 109045 / 1.2 x 104
V = 9.1 m/s
This part of my answer is the same as the textbook's answer. It's the direction of the velocity that differs.
θ = 77°
Since the momentum of the lighter second truck is in the north west quadrant:
180° - (77° + 51°) = 53°
Therefore, the velocity of the second truck is 9.1 m/s [53° N of W]
The textbook says that the velocity is [26° N of W]
Can anyone check if this is right?