# Homework Help: Dragster force?

1. Sep 12, 2009

### kashiark

1. The problem statement, all variables and given/known data
A 873kg dragster, starting from rest, attains a speed of 26.3 m/s in .59s.
a. Find the average acceleration of the dragster during this time interval.
b. What is the magnitude of the average net force on the dragster during this time?
c. Assume that the driver has a mass of 68kg. What horizontal force does the seat exert on the driver?

Mass = 873kg
Final velocity = 26.3 m/s
Final time = .59 seconds
Initial velocity = 0m/s
Initial time = 0 s
2. Relevant equations
average velocity = (Vf-Vi)/(Tf-Ti)
F=ma

3. The attempt at a solution
a. 26.3/.59= 44.6 m/s²
b. 873*44.6= 3.9*10^4 N
c. I'm not sure...

2. Sep 12, 2009

### howt

Part a and b seems correct, well done..

You already figure out the net force on dragster,
using F=ma.

Part c is the same deal, but
what do you think be sensible value to insert as m ?
Is it affected by the mass of the dragster?

You should be able to figure the answer

3. Sep 12, 2009

### kashiark

Hmmm it's definitely affected by the mass of the dragster, but is the mass of the dragster including the mass of the driver? Perhaps 873-68= 805?

4. Sep 12, 2009

### howt

If you are are having the same accelerating in a heavy vehicle and a light vehicle. In which vehicle you are going to feel a stronger force? or it is the same?

5. Sep 12, 2009

### kashiark

I would think it would be the same; I'm thinking now that the force of the seat on him is really him hitting the seat? 68*44.6=3.0*10³?

6. Sep 12, 2009

### howt

Yup, correct

7. Sep 12, 2009

Thanks :)