Question

A child is playing with a toy car, and it accelerates to the south from 1.2m/s to 6.3m/s. if the toy car's acceleration is 2.75m/s2, what is the amount of time that the child takes to accelerate the car? Show all your work.

Answer 1

t = 1.9 s

Step-by-step explanation:

• By definition, acceleration is the rate of change of velocity with respect to time, which can be expressed as follows:

`a = (v_(f) -v_(o) )/(t_(f) - t_(o) ) (1)`

• If we choose t₀ =0, ⇒ tif = t
• Rearranging in (1), we get:

`v_(f) = v_(o) + a*t (2)`

• Solving (2) for t:

`t =(v_(f)-v_(o))/(a) (3)`

• Replacing by the givens in (3):

vf = 6.3 m/s

v₀ = 1.2 m/s

a = 2.75 m/s²

`t =(v_(f)-v_(o))/(a) = t =(6.3m/s-1.2m/s)/(2.75m/s2) = 1.9 s (4)`