Question

An object accelerates from 20 m/s down to 10 m/s in 5 seconds.

What is the acceleration of the object?

Answer 1

The acceleration of the object is
`-2\ (m)/(sec^2)`

Step-by-step explanation:

we know that

The acceleration is the change in the velocity, divided by the time

Let

v -----> the change in the velocity in m/sec

t ----> the time in sec

`a=(V)/(t)`

we have that

`V_2=10\ m/sec\\V_1=20\ m/sec`

`V=V_2-V_1`

substitute

`V=10-20=-10\ m/sec`

`t=5\ sec`

substitute in the formula

`a=(-10)/(5)=-2\ (m)/(sec^2)`

therefore

The acceleration of the object is
`-2\ (m)/(sec^2)`

Is negative because is a deceleration