Question that I dont know how to answer

  • Thread starter Thread starter shadow1010
  • Start date Start date
AI Thread Summary
To determine the initial speed 'vo' for a car to lose contact with the roadway at the top of a hill, one must analyze the forces acting on the car, particularly the gravitational force and the centripetal force required for circular motion. The critical speed at the top of the hill is derived from balancing these forces, where the normal force becomes zero. If the initial speed exceeds this critical value, the car will maintain contact with the road but may experience increased forces, potentially leading to instability. Understanding the role of the normal force throughout the hill's ascent is crucial, as it varies with the car's position and speed. This problem emphasizes the importance of energy conservation and the dynamics of forces in motion.
shadow1010
Messages
1
Reaction score
0
Hi Guys,
we were given this question, and I have no idea where to start.

A car is coasting without friction toward a hill with height 'h' and ratius of the curvature is 'r'.
(a) what initial speed 'vo' will result in the car's wheels just losing contact with the roadway as the car crests the hill?
(b) what happens if the initial speed of the car is greater than the value found in part (a)?

I have figured out that there are no non-conservative forces acting on the car, so the work (conservative) is equal to the work (total) but I don't know where to go from there...any suggestions?
 
Physics news on Phys.org
So, how does the normal component look all along the hill? Is it the biggest at the top of the hill, is it the smallest? What forces are acting on the car as it goes up the hill? Why am I so concerned about the normal anyway?

You might want to break the problem (a) up into a couple problems, what velocity it needs at the top of the hill to fly off and then how that velocity relates to the initial one (you're energy thoughts for this part are good).
 

Thread 'Struggling to understand the concept of this question (ice cube in water optics question)'

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...
View full post »
Thread 'Variable mass system : water sprayed into a moving container'

Thread 'Variable mass system : water sprayed into a moving container'

Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
View full post »

Similar threads

Inconsistent problem about centrifugal/contact force
Replies
12
Views
3K
Question About centrifugal force of a moving car
Replies
5
Views
2K
Speed of train car when sand spilling out from it
Replies
17
Views
4K
Work Energy Theorem and Circular Motion
Replies
2
Views
7K
How Does Speed Affect Normal Force at the Crest of a Hill?
Replies
1
Views
3K
How Does the Angle Affect the Height and Speed of a Toy Car on a Track?
Replies
2
Views
18K
Wow much thermal energy was generated by friction?
Replies
5
Views
8K
Calculate power to have the car at a certain speed
Replies
4
Views
2K
Finding Frictional Force and Power Using Work and Energy
Replies
4
Views
3K
Coefficient of Friction question for a cart going down a wooden ramp
Replies
18
Views
3K

Hot Threads

Recent Insights

Back
Top