Here's the question you clicked on:
mgjimenez1
A 600-kg car is going over a curve with a radius of 120 meters that is banked at an angle of 25 degrees with a speed of 30 meters per second. The coefficient of static friction between the car and the road is 0.3. What is the normal force exerted by the road on the car? a) 7240 N b) 1590 N c) 5330 N d) 3430 N e) 3620 N
First thing to do is draw a free-body diagram of the situation.
you can use the formula tan (theta) = v²/gR where theta is your angle, v is your velocity, g the acceleration due to gravity and R your radius
This formula will give you the velocity for which friction is zero, but it will not provide an answer to the question.
What´s is the value for G force?
Try to use the Diagram for solve the problem.
Here is the answer.
@Dikawar You went right, but it is even easier to project along the normal of the road: - only one projection needed - no system to solve for N, as f does not appear in the equation.
@Dikawar Have a look at the solution I wrote here (you'll have to scroll down to the one with the drawing): http://openstudy.com/study?version=feed:join-study-group&referrer=mit%208.01%20physics%20i%20classical%20mechanics,%20fall%201999&domain=ocw.mit.edu#/updates/50bc2ea4e4b0bcefefa06b4d
*sorry @Diwakar
@Vincent-Lyon.Fr Thanks! Your method is much better and easier .