# BASIC Centripetal Force PROBLEM HELP!

1. Nov 20, 2006

### 8parks11

Calculate the centripetal force on a 2000-kg automobile roudning a curve of 175 m radius at a speed of 50 km/h.

ok
so this

Fc=mv^2/r
i did 2000(50)(1000)(3600) / 175

but this was incorrect. the answer is 2.2x10^3 N

the 1000x3600 was to convert the km/h to m/s and i think that's correct so what did i do wrong here.

2. Nov 20, 2006

### lotrgreengrapes7926

The conversion is $$\frac{1}{1000}\frac{\text{km}}{\text{m}}$$, not $$1000\frac{\text{km}}{\text{m}}$$

3. Nov 20, 2006

### 8parks11

thx for pointing that out but.
i should be getting around 2200.

so i do

2000[(50)(.001)(3600)]^2 / 175
but i get 370285...
whats wrong here now?

4. Nov 20, 2006

### 8parks11

wait still... isn't 50km = 50000m?
so i should multiply 50x1000?

5. Nov 20, 2006

### 8parks11

iim keep getting 2057 if i use 0.01

6. Nov 20, 2006

### lotrgreengrapes7926

Sorry, the hour to second conversion should be changed, not the km to meters.

7. Nov 20, 2006

### 8parks11

ok so if i do multiply 1000 or do "2000(50)(1000)(3600) / 175"
i dont get the answer 2.2x10^3 N