Imagine that you have discovered a way to create a repulsive force field and you
ID: 1332940 • Letter: I
Question
Imagine that you have discovered a way to create a repulsive force field and you are trying to use it to make a device to protect against car crashes. Your device is mounted in a 1000-kg car and is capable of exerting a constant repulsive force of 200,000 N on another car until the cars come to rest with respect to each other. Generating the force field creates a lot of electric power, though, and you are trying to decide how big a battery you need to use. You want the battery to be able to supply power long enough to bring the cars to rest with respect to each other (not necessarily the road) when the protected car is involved in a head on collison with a 2000-kg car when both are traveling at 30 m/s on frictionless ice. How long must your battery be able tmo supply power to the force field?
THE ANSWER IS: 0.20 SEC.....please show the work of how this answer was reached.
Explanation / Answer
net force = average momentum/time
time = average momentum/net force
time=(m1v1+m2v2)(/2*netforce)
time=45000/2300000=0.1956 sec
time=0.2 sec