# Physics 1 Question?

A 1400 kg automobile moving at 35 m/s has the brakes slams on the breaks, resulting in an acceleration of -7.5 m/s2. What is the distance x the car travels before it comes to a stop?

### 1 Answer

- 3 weeks ago
The way to solve these sorts of motion word problems (relatively simple motion problems in physics)

is to find out all of the variables you know

and the variable you need

and then find the equation of motion that fits that information

and plug in the values and solve.

SO: variables we know

M = 14500 kg

Vzero = 35 m/s

V = 0 (the car comes to a stop)

A = -7.5 m/s/s

What we want to know

X - Xzero = distance

Which equation of motion has all of its variables filled by what we know, except for the variable that we want to know (X-Xzero)??

This one:

V-squared - Vzero-squared = 2A(X - Xzero)

So: just plug in the numbers and solve for X-Xzero