# force questions need help ...

#### zelda1850

Joined Jan 3, 2010
18
A manufacturer's advertisement claims that their 1,250 kilogram sports car can accelerate on a level road road from 0 to 26.8 meters per second in 3.75 second.

1) the coefficient of friction between the cars tire and road is 0.80. caculate the force of fiction between the cars tire and road.

ff = u*fn

so to find force normal i have to do m*g which is 1,250 kg * 9.81m/s and do 0.80 n * the fn?

is that correct?

2) using the value for the force you have calculated explain weather or not the manufacturer claim the cars acceleration is possible

how do i know if the accleration is possible?

#### retched

Joined Dec 5, 2009
5,197

..sorry, couldn't resist...

#### ixisuprflyixi

Joined Sep 16, 2007
52
A manufacturer's advertisement claims that their 1,250-kilogram (12,300-newton) sports car can accelerate on a level road from 0 to 60.0 miles per hour (0 to 26.8 meters per second) in 3.75 seconds.
The net force required to give the car the acceleration claimed in the advertisement is 8940 N
The maximum force of friction between the car's tires and the road is 9800 N.
Using these values for the forces,please explain why the manufacturer's claim for the car's acceleration is possible.

Maximum force of friction is 9800N which means the car can produce 9800 N of force before the tires start to slip but only 8940 N is needed to get the car to the acceleration needed. so Yes the car can make the required acceleration within the required time.

#### ixisuprflyixi

Joined Sep 16, 2007
52
26.8/3.75= 7.146666666667 (7.15 rounded) This is your Acceleration A=dV/dT

1,250*7.15= 8937.5 (8940 rounded) This is the force needed to accelerate because F=ma

1250*9.8= (12250) times the coefficient of friction(.8) 12250*.8= 9800 Which is the force of friction

#### loosewire

Joined Apr 25, 2008
1,571
Here I go again I have won a few drag races. It really a thrill
when the crowd wants a (by). That means you get to go to
the head of the line and race again. After you do it once you
will not hope for pleasure again. After a race your car is to heated
to race again,you may be treated to a good dose of humble pie.