Drag Force and Power on an inclined plane

AI Thread Summary
To calculate the power required for a 710 kg car driving at 23 m/s with a drag force of 500 N, the formula P = Fv is applied. For level ground, the power is calculated as P = (500 N)(23 m/s), resulting in 11,500 W. When driving uphill at a 2-degree slope, the total drag force includes the gravitational component, calculated as 500 N + (710 kg)(9.8 m/s²)(sin(2°)). This results in a power requirement of approximately 17,085 W. The discussion emphasizes the importance of incorporating the slope's effect on the total drag force when calculating uphill power requirements.
kraaaaamos
Messages
20
Reaction score
0

Homework Statement



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?


Homework Equations



P=Fv


The Attempt at a Solution



a) P = (500)(23)?

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

I HAVE NO IDEA.
 
Physics news on Phys.org
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)
 
so for b
its:


P = (500+ mgsin(theta))(v)
= [500 + (710)(9.8)(sin2) ](v)
= 17 085 W?
 
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.
 
Kindly see the attached pdf. My attempt to solve it, is in it. I'm wondering if my solution is right. My idea is this: At any point of time, the ball may be assumed to be at an incline which is at an angle of θ(kindly see both the pics in the pdf file). The value of θ will continuously change and so will the value of friction. I'm not able to figure out, why my solution is wrong, if it is wrong .
TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
Back
Top