Question

A car travels at a speed of 55 km/hr and slows down to 10 km/hr in 20 seconds. What is the acceleration?

Answer 1

It would be 10.00

Step-by-step explanation:

Hope this helps its different for everyone what was it for u it was D for me

Answer 2

a = 0.62 [m/s²]

Step-by-step explanation:

To solve this problem we must use the following equation of kinematics. But first, we must convert speeds from kilometers per hour to meters per second.

`v_(f) =v_(o) -a*t`

`55[(km)/(hr)]*(1hr)/(3600s)*(1000m)/(1km) =15.27[(m)/(s) ]\\10[(km)/(hr) ]*(1hr)/(3600s)*(1000m)/(1km) = 2.77[(m)/(s) ]`

where:

Vf = final velocity = 2,77 [m/s]

Vo = initial velocity = 15.27 [m/s]

t = time = 20 [s]

a = acceleration [m/s²]

Now replacing:

`2.77=15.27-a*(20)\\20*a=12.49\\a = 0.62[m/s^(2)]`