00:01
In this problem, you have a car that's traveling up the slope, and you want to find the power necessary for the car to do this.
00:07
So we're given the mass of the car, which is 2 million grams, but we can convert that by divided by 1 ,000 to get 2 ,000 kilograms.
00:20
So then its weight when you multiply it times gravity is 19 ,600 newtons.
00:30
The angle of the slope in 7 degrees and the velocity that the car is traveling with which 100 kilometers per hour we can convert that to 27 .8 meters per second and finally we're given the efficiency of the engine which is epsilon is equal to 0 .65.
01:00
Well we know that the efficiency of any engine is the power output of the engine divided by the power input.
01:12
And power input is what we're looking for.
01:14
So if we solve for pn, we have the power output divided by the efficiency of the engine.
01:29
So if you look at power output, we know it's the force times the velocity, but because the car is traveling upwards, is the velocity in the y direction, which is vy.
01:46
And because in trigonometry, we know that vy is v -syne theta...