Collisions in 2 Dimensions 2-D Collision Analysis! 4wwphs.sharpschool.com/UserFiles/Servers/Server_10640642/File/Bu… · 4 kg 8 kg 8 m/s 30° 30° 24 m/s 12 m/s Whiteboard Watermelon

Buggé: Momentum 4

Collisions in 2 Dimensions

4.1 A car with a mass of 950 kg and a speed of 16 m/s approaches an intersection, as shown to the right. A 1300 kg minivan traveling at 21 m/s is heading for the same intersection. The car and the minivan collide and stick together. Find the speed and direction of the wrecked vehicles just after the collision, assuming that frictional forces can be ignored. (13.8 m/s, ~ 61 degrees)

4.2

4.3 A golf ball strikes a hard, smooth floor at an angle of 30o and rebounds at the same angle. The mass of the ball is 0.047kg and its speed is 45 m/s just before and after striking the floor.

a. What is the impulse applied to the golf ball by the floor? (2.12 kg m/s) b. If the golf ball is in contact with the floor for 10ms, what is the average force that

the ball applies on the floor? (211 N)

24 kg

12 kg

4 kg 8 kg

8 m/s

30° 30°

24 m/s 12 m/s

Whiteboard Watermelon Time! Calculate the total momentum of the system

a)  Before the explosion b)  Immediately after the explosion

2-D Collision Analysis! A car with a mass of 950 kg and a speed of 16 m/s approaches an intersection, as shown below. A 1,300-kg minivan traveling at 21 m/s is heading for the same intersection. The car and the minivan collide and stick together. Find the speed and direction of the wrecked vehic les jus t a f te r the collision, assuming that frictional forces can be ignored.

Buggé: Momentum 4

4.4 You are skating on ice and unintentionally crash into a person. Your mass is 60-kg, and you are traveling east at 8.0 m/s with respect to the ice. The mass of the other person is 80-kg, and he is traveling north at 9.0 m/s with respect to the ice. You hang on to each other after the collision. In what direction and at what speed are you traveling just after the collision? (6.18 m/s at 56.3 degrees)

4.5 A 3000 kg space capsule is traveling in outer space with a velocity of 200 m/s. In an effort to alter its course it fires a 25 kg projectile perpendicular to its original direction of motion at a speed of 2000 m/s. What is the new speed of the space capsule and by what angle has its direction changed? (201 m/s at 4.76 degrees) 4.6 A 1.2 kg grenade is at rest on a smooth surface when it suddenly explodes into three pieces. A 0.5 kg piece flies off to the north at 3 m/s and a 0.3 kg piece flies off southwest at 4 m/s. What is the speed and direction of the third piece? (2.675 m/s at 322 degrees) 4.7 Two cars of unequal mass moving at the same speed collide head-on. Explain why a passenger in the smaller car is more likely to be injured than one in the larger car. Justify your reasoning with the help of physics principles. 4.8 A 0.020-kg bullet traveling at a speed of 300 m/s embeds in a 1.0-kg wooden block resting on a horizontal surface. The block slides horizontally 4.0 m on a surface before stopping. Determine the coefficient of kinetic friction between the block and surface. 4.9 A 10-kg sled with 30-kg Sarah sitting on top of it glides on a horizontal, frictionless surface at speed 4.0 m/s toward the east. Sarah jumps off the back of the sled, and the sled shoots forward toward the east at 12 m/s. What was the Sarah's velocity in the horizontal direction relative to the ground at the instant she left the sled? What does your system have to be in order to solve this problem?