# How Fast is the Car Going Based on Passenger Force Components?

• hayowazzup
In summary, the car is travelling at a speed of 68.9 km/h. The horizontal and vertical components of force on a passenger are 215.0 N and 510.0 N, respectively. To solve for the speed, the equation v = √(rg 215/510) can be used.
hayowazzup
[SOLVED] Need help with finding the speed

## Homework Statement

A car goes around a curved stretch of flat roadway of radius R = 94.0 m. The magnitudes of the horizontal and vertical components of force the car exerts on a securely seated passenger are, respectively, X = 215.0 N and Y = 510.0 N.

At what speed is the car travelling?

i have no idea how to solve this.

not quite sure

## The Attempt at a Solution

:(

a= v^2 / r
v = SQRT(ar)
Y=F =510N= mg , m= 510/9.8=52.04
X=F= 215N=ma , a= 215/52.04=4.13
v= SQRT(4.13*94)

Last edited:
hayowazzup said:
a= v^2 / r
v = SQRT(ar)
Y=F =510N= mg , m= 510/9.8=52.04
X=F= 215N=ma , a= 215/52.04=4.13
v= SQRT(4.13*94)

Hi hayowazzup!

Yes that looks good …

though I'd have shortened it by writing v = √(rg 215/510) …

then you can do all the calculation in one go.

umm i got 19.13m/s
Convert it now km/h, 19.13 * (1000/(60*60))= 5.315km/h
but the answer in the book is 68.9km/h

hayowazzup,

I believe your conversion factor is upside down; you divide by 1000 to convert from meters to km, and you multiply by 3600 to convert from (1/s) to (1/hours).

## 1. What is speed?

Speed is a measure of how fast an object is moving in a specific direction. It is usually expressed in units of distance per unit of time, such as meters per second or miles per hour.

## 2. How do you calculate speed?

To calculate speed, you need to know the distance an object has traveled and the time it took to travel that distance. The formula for speed is speed = distance / time. Make sure to use the same units for distance and time.

## 3. Can speed be negative?

Yes, speed can be negative. This means that the object is moving in the opposite direction of the one being measured. For example, if an object is moving west and its speed is measured as -10 m/s, it means it is moving 10 meters per second to the east.

## 4. What factors affect an object's speed?

The main factors that affect an object's speed are its distance traveled and the time it takes to travel that distance. Other factors such as the object's mass, force applied, and surface conditions can also impact its speed.

## 5. How is speed different from velocity?

While speed is a measure of how fast an object is moving, velocity is a measure of both speed and direction. In other words, velocity takes into account the object's movement in a specific direction, while speed only looks at the magnitude of its movement.

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