(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A block is hung by a string from the inside roof of a van. When the van goes straight ahead at a speed of 28m/s, the block hands vertically down. But when the van maintains this same speed around an unbanked curve (radius=150m), the block swings toward the outside of the curve. Then the stringmakes an angle A with the vertical. Find angle A.

2. Relevant equations

F=mv^2/r???

FsMax = (mew)s Fn ???

Mew = coefficient of static friction.

3. The attempt at a solution

Managed to find coefficient of static friction by equating the two equations above and substituting w=mg=Fn. Coefficient based on my calculatinos was 0.53. Didn't help me answer the question.

Then I reasoned that based on a drawing, which may be flawed, that tanA = Fn/r. Fn= normal force which would lead to equating FsMax = Mv^2/r. Couldn't find the mass though. If I had found the mass, I could find one of sides of hte triangle the angle is in and since radius is given, it would be easy to determine angle A.

**Physics Forums | Science Articles, Homework Help, Discussion**

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Unbanked curve problem

**Physics Forums | Science Articles, Homework Help, Discussion**