Math based ( distance traveled )

Question

I have tried numerous times to come up with an answer for this question And was hoping to get some help.

 

i Would like to know if a car starts at 0 miles per hour and can reach 40 miles per hour in 3.5 seconds. How far does the car travel in that 3.5 seconds. I don’t understand how to calculate the cars distance because the speed in constantly increasing. 

Answer 1

If the acceleration is constant, you can use the formula

 

d = at²/2 + v₀t

 

d = distance traveled from starting position

t = travel time = 3.5 sec

v₀ = initial speed = 0 mph  [given]

a = constant acceleration

 

a = Δv/t = (v₁ - v₀)/t

v₁ = 40 mph

v₀ = 0 mph

t = 3.5 sec

 

I suggest you either convert speeds to ft/sec, keep the time in seconds, and get d in feet; or convert time to hours, work with speed in mph, and get d in miles.  Then plug the numbers into the formulas for acceleration and distance.