A particular race car can cover a quarter-mile track (402 m) in 6.40 s starting from standstill. Find its acceleration.

If the combined mass of the driver and race car is 485 kg, what horizontal force must the road exert on the tires?

9520N

Explanation:

For the first part of this problem:

Given parameters:

Distance traveled  = 402m

Time taken  = 6.4s

Initial velocity  = 0m/s

Unknown:

Find the acceleration  = ?

Solution:

To solve this problem, we use on of the kinematics equation:

                S  = ut   +  at²  

S is the distance moved

u is the initial velocity

t is the time taken

a is the acceleration

             402  = (0 x 6.4) + ( x a x 6.4²)

            402 = 20.48a

              a = 19.63m/s²

Second problem:

Given parameters:

Mass of the driver and race car combined  = 485kg

So;

 Horizontal force  = mass x acceleration

 Horizontal force  = 485 x 19.63  = 9520N

what was the answer?

0.19 m/s and 0.45 m/s