The car is accelerating from a stop at a rate of 43 m/s2. How long will it take to
reach 86 m/s?

2 s

Explanation:

Since the car is accelerating from a stop, it has an initial velocity of 0 m/s. The acceleration of the car is 43 m/s².

We want to find the time it takes for the car to have a final velocity of 86 m/s.

We can relate all four of these variables (initial velocity, final velocity, acceleration, time) in this kinematic equation:

Substitute the known variables into the equation.

It will take the car 2 seconds to reach 86 m/s.

2 seconds

Explanation: In physics (m/s^2) meters per second squared or meters per second per second, literally means by how many meters per second the velocity changes every second. In this case it is 43. The car moves 43 meters a second per every second. That means that the car would move 86 meters in 2 seconds, 129 in 3 seconds, and so on.

(+) In cases like this, the fastest way to find the answer is to do simple division.

86/43 = 2

(Example) Look at it this way, the car is going 45 miles per hour. How long will it take to reach 90 miles? If the car goes 45 miles per hour, that means in 2 hours it will reach 90 miles.

90/45 = 2

Simple division.

Your very welcome, let me know if you have any questions. :-)

-szimbitskyy