BEFORE COLLISION 300 kg 1 200 kg 2 000 kg Ooo 0 AFTER COLLISION (2) (5) (4) 7.1 Write down magnitude and direction of the 'reaction force' to the weight of truck A 7.2 Calculate the velocity of truck B after the collision 7.3 Calculate the magnitude of the force that truck A exerts on truck B if the collision lasts for 0,5 s. 8 The most common reasons for rear-end collisions are too short a following distance, speeding and failing brakes. The sketch below represents one such collision. Car A of mass 1 000 kg, stationary at a traffic light, is hit from behind by Car B of mass 1 200 kg, travelling at 18 ms Immediately after the collision Car A moves forward at 12 ms!

Air is held within a frictionless piston-cylinder container, which is oriented vertically. the mass of the piston is 0.45 kg and the cross-sectional area is 0.0030 m2. initially (state 1) the pressure of the gas is sufficient to support the weight of the piston as well as the force exerted by the atmospheric pressure ( 101.32 kpa). the volume occupied by the air within the cylinder in state 1 is 1.00 liter. one end of a spring (with spring constant k = 1000 n/m) is attached to the top of the piston, while the other end of the spring is attached to a stage that can move vertically. initially the spring is undeflected and therefore exerts no force. then the stage is then moved quasistatically downward a distance of 10.0 cm, at which point the system reaches state 2. the piston-cylinder is not insulated; rather it remains in diathermal contact with the surroundings, which are at a constant temperature of 300 k. what is the change of pressure within the container?

1.in one challenge on the titan games, competitors have to lift 200 pounds up a long ramp. angel is able to move the weight in 42 seconds. anthony gets it done in only 38 seconds. which statement is true? angel has more power than anthony. angel does more work than anthony. anthony does more work than angel. anthony has more power than angel. 2.a mountain climber exerts 41,000 j of work to climb a cliff. how much power does the climber need if she wants to finish in only 500 seconds? power = work / time 20,500,000 watts 82 watts 0.0122 watts 41,500 watts 3.your family is moving to a new apartment. while lifting a box 83 joules of work is done to put the box on a truck, you exert an upward force of 75 n for 3 s. how much power is required to do this? (hint: you only need two of the 3 numbers given! ) power = work / time 249 watts 25 watts 2075 watts 27.7 watts

Red’s momentum vector before the collision is green’s momentum vector after the collision. question 1 options: shorter than longer than equal to question 2 (1 point) saved since green bounces off red, this must be an collision. question 2 options: explosion inelastic elastic question 3 (1 point) saved red transfers of its momentum to green during the collision. question 3 options: little all most none question 4 (4 points) why does red transfer all its momentum to green? back up your answer with information from the simulation. write at least 2 sentences. question 4 options: skip toolbars for . more insert actions. more text actions. more paragraph style actions. question 5 (1 point) now make red much heavier than green. answer the questions below to describe how both red and green behave after the collision. you might want to play the sim multiple times. click on restart or return balls to start over. to see numbers, check the show values box (inside the green box). red during the collision because it transferred some momentum to green. question 5 options: sped up kept the same velocity slowed down question 6 (1 point) green sped up during the collision as it question 6 options: lost momentum to red maintained a constant momentum. gained momentum from red question 7 (1 point) after the collision . . question 7 options: red bounced off green and went to the left. green moved to the right. both green and red stopped as they have lost all momentum. red stopped and green moved to the right. both green and red moved to the right. question 8 (4 points) only some of red’s momentum was transferred to green. why did this occur? back up your answer with information from the simulation. write at least 2 sentences. question 8 options: skip toolbars for . more insert actions. more text actions. more paragraph style actions. question 9 (1 point) now make red much lighter than green. answer the questions below to describe how both red and green behave after the collision. you might want to play the sim multiple times. click on restart or return balls to start over. to see numbers, check the show values box (inside the green box). which is true about the collision? question 9 options: green slowed down after the collision therefore it must have lost momentum. green sped up after the collision therefore it must have lost momentum. green sped up after the collision therefore it must have gained momentum. green slowed down after the collision therefore it must have gained momentum. question 10 (1 point) since green gained momentum, red had to have momentum because you cannot create or destroy momentum. question 10 options: lost kept the same amount of gained question 11 (1 point) since green was so much and harder to move, it caused red to bounce back to the left giving red . question 11 options: lighter. . . . negative heavier . . . . negative lighter. . . . positive heavier . . . . positive question 12 (4 points) now, click on more data at the bottom of the sim. play with different numbers for the masses and starting velocities. you can even make the starting velocities negative! tell me one thing you discovered by adjusting the speeds and masses. write at least 2 sentences. be specific and use words like velocity, momentum, mass, increased, decreased, etc. question 12 options: skip toolbars for . more insert actions. more text actions. more paragraph style actions. part 2: inelastic collisions question 13 (1 point) click on the "less data" box at the bottom of the sim. in the green box, slide the elasticity meter all the way to inelastic so there is 0% elasticity: make the masses whatever size suits you. make sure that green starts out with a velocity of 0 m/s – if you didn’t change this in the last step, you don’t need to do anything. push play and observe! true or false: when red and green collide, they stick together. question 13 options: true false question 14 (1 point) the velocity of red & green after the collision is the velocity that red started off with. question 14 options: larger than smaller than equal to