Physics Unit 4 Review Guide PDF

Physics Unit 4 Review Guide keine he Name: __________________________________...

Physics Unit 4 Review Guide keine he Name: __________________________________ Period: __________________________________ 1. A car on a freeway collides with a mosquito, which was initially at rest. The mosquito sticks to the front of the car. Justify all answers thoroughly. a. Did the total momentum of the car-mosquito system increase, decrease, or remain the same? Why? Remains the same becausemomentum is conserved in the absence of externalforces b. Did the momentum of the mosquito increase, decrease, or remain the same? Why? 1 Jan starts at rest and Teymosavito c. Did the momentum of the car increase, decrease, or remain the same? Why? as the car transfers momentum reeesmsjqt.tt d. Which changed its velocity more in the collision, the car or the mosquito (or did they change by the same amount?). Why? The mosquito as its smaller mass causes a greatervelocitychange e. Which changed its momentum by more in the collision, the car or the mosquito? (or did they change by the same amount?) Why? the momentum lost59min it smogma.tn amaisfn si tu f. Which experience a greater impulse in the collision, the car or the mosquito? (or did they change by the same amount?) same Why? for both Impulse is equal in magnitude but opposite in direction for the car and mosquito Newton's third law 2. Rank these three objects in increasing order of impulse, beginning with the smallest, and increasing order of force acting on the object beginning with the smallest. Object A Object B Object C m = 5.0 kg m = 10.0 kg m = 4.0 kg vi = 4.0 m/s vi = 2.0 m/s vi = 5.0 m/s vf = -2.0 m/s vf = -2.0 m/s vf = -2.0 m/s t = 12.0 s t = 5.0 s t = 2.0 s Impulse: 2 A: ______________ 3 B: _____________ 1 C: ______________ Force: 1 A: ______________ 2 B: _____________ 3 C: ______________ A 5.0kg 2.0 40m s 30.0ns A F 30 122.5N B 10.0kg 2.0 2 0 m s 40.0ns B F 4015 8N 4.0kg 2.0 5.0 m s 28.0Ns C F 28 2 14N 3. If a 20 kg object moving at 3 m/s experiences an impulse (shown in the graph to the right), what is the final velocity of the object after the impulse? I m Vf Vi 6 24 80 20 Vf 3 80 88 204188 16 24 10 140 20vf To To of 7m S 4. Car 1 has a mass of 1200.0 kg and goes from 34.0vi Vf m/s to 14.0 m/s in 12.0 s. Car 2 also has a mass of 1200.0 kg and goes from 20.0 m/s to 0.0 m/s in 8.0 s. Which car experiences the bigger impulse (if any) and which car experiences the larger force (if any). EI.EE i i xm ineus 5. É s 3,089 care has abiggerforce A 10 kg cart moving at 7 m/s crashes into a 5 kg cart moving towards it at 3 m/s. The 5 kg cart rebounds at a speed of 10 m/s. What is the final speed of the 10 kg cart? What type of collision is this? loursxc.io 7 13 0 3 10.5m s Elasticcollision 6. Two ice skaters face each other on a frictionless surface and push off of one another sending them in opposite directions. Skater A has a mass 70.0 kg and moves at a velocity of 2.50 m/s. Skater B has a mass of 55.0 kg and moves in the opposite direction of Skater A. What is Skater B’s final velocity. What type of collision is this? 70 2 50 55 v 0 175 550 v 3.18m s Explosioncollision 7. A 100 kg cart moving at 5 m/s crashes into a 75 kg cart moving towards it at 3 m/s. The 100 kg cart keeps moving forward at a velocity of 1.2 m/s. What is the final speed of the 75 kg cart? What type of collision is this? 180EE 92oE33;100x1.2 75 1E2 09mIs Elastic collision 8. A child in a boat throws a 5.30-kg package out horizontally behind them with a speed of 10.0 m/s. Calculate the velocity of the boat immediately after, assuming it was initially moving forward at a velocity of 2 m/s. The mass of the child is 24.0 kg and the mass of the boat is 35.0 kg. What type of collision is this? 24 35 2 5.30 10 24 35 v 118 59nF 53 59 5.08m's Explosioncollision 9. A 7150-kg railroad car travels alone on a level frictionless track with a constant speed of 15 m/s. A 3350-kg load, initially at rest, is dropped onto the car. What will be the car’s new speed? (3 points) 7150 15 3350 0 7150 3350v 107,250 10,5000 10.21m s Inelasticcollision 10. A 1500.0 kg car traveling 5.00 m/s collides head on with a 3000.0 kg truck traveling 7.00 m/s in the opposite direction. If the bumpers lock. a. what is the velocity of the two vehicles together immediately following the collision? 1500 5 3000x 7 4500 Vf 7500 21,000 4195 15 Vf 3M S b. what is the impulse experienced by the driver of each car during the collision? car 1500 3.0 5.0 1500 8 12,000ns Truck 3000 3 7 0 3000 4 12,000ns c. Cars have crumple zones to minimize the force the driver experiences in a collision. Using the impulse-momentum theorem, explain how crumple zones decrease the force. Crumplezones increase of byabsorbing energyduringimpact which reduces the force experienced by the driver Extra Help Problems: These problems aren’t required but are designed to provide additional practice Impulse Graph 1 Impulse Graph 2 Explosion Collision Inelastic Collision Inelastic Collision Inelastic Collision 1 2 3 Link Here Link Here Link Here Link Here Link Here Link Here