Question

An automobile accelerates 1.77 m/s/s over 6.00 s to reach freeway speed at the end of an entrance ramp. If the car's final speed is 88.0 km/h, what is the initial speed when it began accelerating?

Answer 1

`49.75\ \text{km/h}`

Step-by-step explanation:

a = Acceleration of the automobile =
`1.77\ \text{m/s}^2`

t = Time taken = 6 s

v = Final velocity = 88 km/h =
`(88)/(3.6)=24.44\ \text{m/s}`

u = Initial velocity

From the linear equations of motion we have

`v=u+at\\\Rightarrow u=v-at\\\Rightarrow u=24.44-1.77* 6\\\Rightarrow u=13.82\ \text{m/s}=13.82* 3.6=49.75\ \text{km/h}`

The initial speed when the automobile started accelerating is
`49.75\ \text{km/h}`.