Please show your work.
1. a 2000 kg SUV is moving at 25 m/s. What force is needed to bring it to a stop in 8 seconds?
2. A 20 kg child is sitting in a 15 kg wagon that is moving at 3 m/s. what is the total momentum in the system?
3. A 75 kg train car moving at 2.4 m/s collides with a second identical train car at rest. if they hook together when the collide, what is the final speed of the two?
4. a 4000 kg train car moving at 2.4 m/s. same question as 3.
5. a 6 kg bowling ball and a 4 kg bowling ball are rolled toward each other. the 6 kg ball is initially moving at 5.1 m/s and the 4 kg ball is moving in the opposite direction at 1.3 m/s. if the 6 kg ball slows to 1.5 m/s, what is the final speed of the 4 kg ball?
please help
me with this question.
1. Force = mass x acceleration
Force = 2000 kg x (-25 m/s / 8 s)
Force = -312.5 kN
2. Momentum = mass x velocity
Momentum = (20 kg x 3 m/s) + (15 kg x 3 m/s)
Momentum = 105 kg m/s
3. Momentum is conserved in a collision, so the total momentum of the two train cars before and after the collision must be the same.
Momentum before = (75 kg x 2.4 m/s) + (75 kg x 0 m/s)
Momentum before = 180 kg m/s
Momentum after = (75 kg x v) + (75 kg x v)
Momentum after = 150 kg m/s
v = 1.2 m/s
4. Momentum before = (4000 kg x 2.4 m/s) + (4000 kg x 0 m/s)
Momentum before = 9600 kg m/s
Momentum after = (4000 kg x v) + (4000 kg x v)
Momentum after = 9600 kg m/s
v = 1.2 m/s
5. Momentum before = (6 kg x 5.1 m/s) + (4 kg x -1.3 m/s)
Momentum before = 11.3 kg m/s
Momentum after = (6 kg x 1.5 m/s) + (4 kg x v)
Momentum after = 11.3 kg m/s
v = -2.7 m/s