a car of mass 1500kg is moving up a straigt road,which is inclined at an angle *to the hrizontal,where sin*=1/14,the res
问题描述：
a car of mass 1500kg is moving up a straigt road,which is inclined at an angle *to the hrizontal,where sin*=1/14,the resistance to the motion of the car from non-gravitional forces is constant and is modelled as a single constant force magnitude 650N.The car's engine is working at a rate of 30kw.
find the acceleration of the car at the instant when its speed is 15m/s.
答
重力在平行路面方向的分量=mgsinα=1500×9.8×(1/14)=1050(N)
∵发动机输出功率恒定在30KW
∴当小车速度为15m/s是,发动机输出的拉力=30KW/(15m/s)=2000N
∴此时小车的加速度a=(2000N-1050N-650N)/1500KG=0.2m/s²