Posted by **Matthew Goldberg** on Friday, June 15, 2012 at 9:07pm.

Driving in your car with a constant speed of v = 11.7 m/s, you encounter a bump in the road that has a circular cross section, as indicated in the figure below. If the radius of curvature of the bump is r = 34.4 m, calculate the apparent weight of a 65.9 kg person in your car as you pass over the top of the bump.

I honestly don't even know where to start with this question. I am having a very hard time with apparent weight in general so please don't criticize me. Thank you for any and all help!

- PHYSICS -
**drwls**, Friday, June 15, 2012 at 9:18pm
Assume that car tires and shock absorbers do not "cushion" the bump, so that the passenger's center of mass follows the profile of the bump.

The apparent weight is the force that the seat applies to the person to keep him or her in place. At the top of the bump, less force is required because there is a downward centripetal acceleration.

The person's actual weight is M g = 645.8 N

That gets reduced by

M V^2/R = 262.2 N

temporarily, due to the bump

The apparent weight is then 383.6 N

- PHYSICS -
**Damon**, Friday, June 15, 2012 at 9:22pm
The centripetal acceleration is down, toward the center of the circle

Ac = v^2/R = 11.7^2/34.4 = 3.98 m/s^2

The gravity force down on driver = m g = 65.9*9.8 = 646 Newtons

The force up on the driver from the car is F, the weight a scale would measure if placed on the seat.

so

total force down on driver = m (Ac)

646 - F = 65.9 (3.98)

F = 646 - 262

F = 384 Newtons

## Answer this Question

## Related Questions

- Physics - Driving in your car with a constant speed of 12 , you encounter a bump...
- Physics - Driving in your car with a constant speed of 12 m s you encounter a ...
- physics - Driving in your car with a constant speed of 12 m/s, you encounter a ...
- Physics - Driving in your car with a constant speed of v=13.0 m/s, you encounter...
- physics - Driving in your car with a constant speed of 12 m/s, you encounter a ...
- physics - driving in a car with constant speed of 12m/s,then encounter to a bump...
- physics - You are driving your car over a circular-shaped bump in the road that ...
- physics - You are driving your car over a circular-shaped bump in the road that ...
- Physics - An 893 kg car passes over a bump in a road that follows the arc of a ...
- physics - In the figure below, a stuntman drives a car (without negative lift) ...

More Related Questions