Car driving up the hill

  • Thread starter domagoj412
  • Start date
  • #1

Homework Statement


Car is driving up the hill with speed of 60 km/h. Angle of incline is 17°. Seeing barrier on the road, the driver suddenly stops (breaks the wheels) and starts to slide. If koef. of fiction is [tex]\mu[/tex]=0.6 what is the distance between breaking point and the point when cars stops. Solve the problem with the same parameters when the car is driving down the hill.

(I hope you understand the question, it is a little difficult for me to translate it...)

Homework Equations


Again, I solve it but I'm not sure if is correct..


The Attempt at a Solution



Uphill:
Ek = Ep + Fk*s
1/2 mv^2 = mgh + [tex]\mu[/tex]*m*g*cos([tex]\alpha[/tex])*s
(h = s * sin([tex]\alpha[/tex]))
...
s = 32,7 m

Downhill:
Ek + Ep = Fk*s
 

Answers and Replies

  • #2
vij
14
0

Homework Statement


Car is driving up the hill with speed of 60 km/h. Angle of incline is 17°. Seeing barrier on the road, the driver suddenly stops (breaks the wheels) and starts to slide. If koef. of fiction is [tex]\mu[/tex]=0.6 what is the distance between breaking point and the point when cars stops. Solve the problem with the same parameters when the car is driving down the hill.

(I hope you understand the question, it is a little difficult for me to translate it...)

Homework Equations


Again, I solve it but I'm not sure if is correct..


The Attempt at a Solution



Uphill:
Ek = Ep + Fk*s
1/2 mv^2 = mgh + [tex]\mu[/tex]*m*g*cos([tex]\alpha[/tex])*s
(h = s * sin([tex]\alpha[/tex]))
...
s = 32,7 m

Downhill:
Ek + Ep = Fk*s

Your equations are correct. But the calculation appears to be incorrect. Probably you have not converted km/h into m/s. Try once again and finish both calculations.
 
  • #3
Yes, I got the different result:

16.34 m for uphill and 50.31 m for downhill.
 
  • #4
vij
14
0
Yes, I got the different result:

16.34 m for uphill and 50.31 m for downhill.

Your answer is correct now.
 

Related Threads on Car driving up the hill

  • Last Post
Replies
7
Views
10K
  • Last Post
2
Replies
48
Views
5K
Replies
45
Views
7K
Replies
2
Views
5K
  • Last Post
Replies
4
Views
934
  • Last Post
Replies
19
Views
6K
Replies
5
Views
2K
Replies
6
Views
3K
  • Last Post
Replies
1
Views
4K
  • Last Post
Replies
5
Views
2K
Top