Motion and force along a curved path

In summary, to find the car's speed on a curved exit ramp with a radius of 82 m, we can use the formula v=2(3.14)r/t and u(static)=v^2/rg. However, since the time is not given, we can instead use the formula F=m*a and calculate the acceleration, then use a=v^2/R to find the speed.
  • #1
a18c18
21
0

Homework Statement



A car speeds along the curved exit ramp of a freeway. The radius of the curve is 82 m. A 76 kg passenger holds the arm rest of a car door with a 220 N force to keep from sliding across the front seat of the car. (Assume the exit ramp is not banked and ignore friction with the car seat.) What is the car's speed?

Homework Equations



v=2(3.14)r/t
u(static)=v^2/rg

The Attempt at a Solution



I tried to use the v=2(3.14)r/t formula but I don't know the time. I'm not sure what else to try.
 
Physics news on Phys.org
  • #2
a18c18 said:

Homework Statement



A car speeds along the curved exit ramp of a freeway. The radius of the curve is 82 m. A 76 kg passenger holds the arm rest of a car door with a 220 N force to keep from sliding across the front seat of the car. (Assume the exit ramp is not banked and ignore friction with the car seat.) What is the car's speed?

Homework Equations



v=2(3.14)r/t
u(static)=v^2/rg

The Attempt at a Solution



I tried to use the v=2(3.14)r/t formula but I don't know the time. I'm not sure what else to try.

You would do better to work from the 220N force on the individual.

F=m*a since this is also equal to mV2/R you know that a = V2/R ... Calculate a. Calculate V.
 
  • #3


I would approach this problem by first considering the forces acting on the passenger and the car. The passenger is exerting a 220 N force on the arm rest to counteract the centrifugal force acting on them due to the curved path. The car is also experiencing a centripetal force towards the center of the curve.

Using Newton's second law, we can equate these forces:

F_c = m*v^2/r

Where F_c is the centripetal force, m is the mass of the car (including the passenger), v is the speed of the car, and r is the radius of the curve.

We can then solve for v:

v = √(F_c*r/m)

Substituting in the given values:

v = √(220 N * 82 m / 76 kg)

v = √(237.9 m^2/s^2)

v = 15.4 m/s

Therefore, the car's speed is approximately 15.4 m/s.
 

1. What is centripetal force?

Centripetal force is the force that acts on an object moving in a curved path, directed towards the center of the curve. It is responsible for keeping an object in circular motion.

2. How is centripetal force calculated?

Centripetal force can be calculated using the formula F = mv2/r, where m is the mass of the object, v is its velocity, and r is the radius of the curve.

3. Can an object move in a curved path without a force acting on it?

No, according to Newton's First Law of Motion, an object will continue to move in a straight line at a constant speed unless acted upon by a force. Therefore, a force is required to change the direction of an object's motion and make it move along a curved path.

4. What is the difference between centripetal force and centrifugal force?

Centripetal force acts towards the center of the curve and keeps an object in circular motion, while centrifugal force is a fictitious force that appears to act in the opposite direction and is caused by the inertia of the object trying to resist the change in its direction of motion.

5. How do forces affect the speed of an object moving along a curved path?

Forces can either increase or decrease the speed of an object moving along a curved path. A force in the same direction as the object's motion will increase its speed, while a force in the opposite direction will decrease its speed.

Similar threads

  • Introductory Physics Homework Help
Replies
12
Views
2K
  • Introductory Physics Homework Help
Replies
7
Views
2K
  • Introductory Physics Homework Help
Replies
4
Views
1K
  • Introductory Physics Homework Help
Replies
6
Views
2K
  • Introductory Physics Homework Help
Replies
3
Views
6K
  • Introductory Physics Homework Help
Replies
6
Views
6K
  • Introductory Physics Homework Help
Replies
3
Views
616
  • Introductory Physics Homework Help
Replies
7
Views
4K
  • Introductory Physics Homework Help
Replies
2
Views
2K
  • Introductory Physics Homework Help
Replies
5
Views
1K
Back
Top