A small vehicle of mass 640 kg is powered by a battery-driven electric motor. The total frictional resistance to motion is 200 N. The car moves up incline at a steady speed of 2.0 m/s.
(There is a diagram provided whereby a right angle triangle is drawn. And the vertical height is 10 m and the hypotenuse is 160 m.)
Calculate
(a) The total work done in bringing the car to the top.
(b) The power the motor must develop to propel the car up the incline.
2007-08-17 22:29:54 · 1 answers · asked by whatagowk 2 in Science & Mathematics ➔ Physics
Total work = resulting force in Y-direction * h (displacement is along Y, this is why i say use resulting force in Y-direction)
Total work = mgh+200N *10/60
Total power = F*v
F exerted by the motor has 2 components: one againts friction and the other against gravity.
F = 200 N + mg* (10/160) = 200 + 640*9.8*10/160
10/160 is sin(alpha) where alpha is the angle between the incline and the base of the incline.
Now calculate F and substitute into expression for Power
2007-08-18 03:26:38 · answer #1 · answered by Snowflake 7 · 0⤊ 0⤋