What is the instantaneous speed (in m/s) at the 10-second mark for a car that accelerates at 2 m/s squared....

Question

What is the instantaneous speed (in m/s) at the 10-second mark for a car that accelerates at 2 m/s squared from a position of rest? I need the answer, but I need a very very very easy to understand explanation for how you got the answer. Thank you.

Answer 1

When they say the car has an acceleration of 2 m/s², it means that every second, the car's speed changes by 2 m/s compared to the second before.

So, for example, if the car happens to be going at 45 m/s at some instant, then one second later it will be going at 47 m/s. One second after that, it will be going at 49 m/s, and so on.

So, apply that to this case, and see how fast the car is going second-by-second:

At 0 seconds (i.e. when you "start the clock"), speed = 0 m/s
After 1 second: speed = 2 m/s
After 2 seconds: speed = 4 m/s
After 3 seconds: speed = 6 m/s

...and so on. I think you can see that, after 10 seconds, the speed will be 20 m/s.

Now think about how you got that answer. (Hint: you multiply something by something else.)

Answer 2

I won't tell you the answer, but I will make a strong hint at it.

If the speed increases by 2 m/s each second, how fast will it be going after 10 seconds? Try multiplying.