Question

For a car of weight 9000 N, the recommended tyre pressure is 18 Pa. Find the area of each
tyre in contact with the ground.
[Ans. 125 ml​

Answer 1

Answer:

125 m^2

Explanation:

According to the given question,

F = Force = 9000 N

P = pressure = 18 Pa

A = Total Area

And we are asked to find the area of each tyre in contact with the ground.

We know,

• P = F/A

• A = F/P

Putting the values we get,

• A = 9000/18

• A = 500 m^2

As there are 4 tyres in a car, thus area of each tyre will be,

• A' = 500/4 = 125 m^2

Where A' = the area of each tyre in contact with the ground.

Answer 2

Solution :-

First we should know these :-

Pressure :- Thrust over a given area (contact area ) . SI unit = Pascal .

Force :- Mass × Acceleration . SI unit = Newton

Now as given :-

Force/Thrust by four wheels of car = 9000 N

Pressure = 18 Pascal .

Now as

$\boxed{\sf{ Pressure = \dfrac{Thrust}{Contact\: Area}}}$

$18 = \dfrac{9000}{\sf{Area \:of\: wheel \: under \: contact \times 4}}$

$\sf{Area \:of\: wheel \: under \: contact \times 4} = \dfrac{9000}{18}$

$\sf{Area \:of\: wheel \: under \: contact \times 4} = 500$

$\sf{Area \:of\: wheel \: under \: contact } = \dfrac{500}{4}$

$\sf{Area \:of\: wheel \: under \: contact } = 125 \: m^2$

So each tyre have 125 m² under contact