# Drag Force and Power on an inclined plane

1. Nov 22, 2007

### kraaaaamos

1. The problem statement, all variables and given/known data

A 710 kg car drives at a constant speed of 23 m/s. It is subject to a drag force of 500N. What power is required from the car’s engine to drive the car
a. on a level ground?
b. up a hill with a slope of 2.0 0?

2. Relevant equations

P=Fv

3. The attempt at a solution

a) P = (500)(23)?

b) P = (500cos2)(23)?

I HAVE NO IDEA.

2. Nov 22, 2007

### rl.bhat

In the second part slope is given. Slope = tan(theta). From that find sin(theta). Now the total drag force during up hill drive = 500 + Mgsin(theta)

3. Nov 22, 2007

### kraaaaamos

so for b
its:

P = (500+ mgsin(theta))(v)
= [500 + (710)(9.8)(sin2) ](v)
= 17 085 W?

4. Nov 22, 2007

### rl.bhat

P = (500+ mgsin(theta))(v)
= [500 + (710)(9.8)(sin2) ](v)
= 17 085 W?

Tan(theta) = 2. Using trigonometrical tables find theta and then find theta or if Tan(theta) = 2. the sin(theta) = (sqrt.5)/2 Use this and find the value.