# Jennifer works for an automaker and tests the safety performance of cars. She watches a 2,000-kilogram car crash into a wall with a force of 30,000 newtons. What’s the acceleration of the car at impact? Use A=v-u/t .

Mar 17, 2018

$a = 15$ ${\text{m" cdot "s}}^{- 2}$

#### Explanation:

It doesn't seem that the formula given can be used to find the acceleration of the car.

The time of acceleration nor the initial and final velocities of the car are provided.

So we must use the formula $F = m a$; where $F$ is the force of impact (in Newtons $\text{N}$), $m$ is the mass of the car (in kilograms $\text{kg}$), and $a$ is its acceleration (in metres per square second ${\text{m" cdot "s}}^{- 2}$).

We want to find its acceleration on impact, so let's solve the equation for $a$:

$R i g h t a r r o w F = m a R i g h t a r r o w a = \frac{F}{m}$

Now, let's plug in the relevant values (which are provided):

$R i g h t a r r o w a = \frac{30 , 000}{2000}$ ${\text{m" cdot "s}}^{- 2}$

$\therefore a = 15$ ${\text{m" cdot "s}}^{- 2}$

Therefore, the acceleration of the car on impact is $15$ ${\text{m" cdot "s}}^{- 2}$.