[填空题]
You are the design engineer in charge of the h,;1gof)ajzrbn a u ;54k f:gscrashb2f -8h thi6zrq2;jc81ufkdc .xiu: c worthiness of new automobile models. Cars are tested by smashing them into fixed, massive barriers at 50km/h (30 mph). A new model of mass 1500 kg takes 0.15 s from the time of impact until it is brought to rest. (a) Calculate the average force exerted on the cc8 rifx hfzuhc ;.2ct 8id1j6qkbu2-:ar by the barrier. $\approx$$a\times10^5$N a =
(b) Calculate the average deceleration of the car. m/$s^2$
