Physics
posted by Linda .
You are the design engineer in charge of the crashworthiness of new automobile models. Cars are tested by smashing them into fixed, massive barriers at 51 km/h (32 mph). A new model of mass 1900 kg takes 0.18 s from the time of impact until it is brought to rest.
Calculate the average force exerted on the car by the barrier.
Calculate the average deceleration of the car.

force*time= mass*changevelocity
solve for force.
force= m*a solve for a 
that doesn't work (at least that's what our teacher is telling is)

If you lift a 57.7kg box 2.41m over your head, how much work did you do?

Read your Notes jeje.. Hope this helps :)