Answer:
Car velocity when crossing checkpoint = 60 m/s
Step-by-step explanation:
For an object traveling at an acceleration of a m/s², with an initial velocity of u m/s the displacement at time = t secs is given in meters by the equation
Here we are given displacement, and time but not acceleration and initial velocity : d = 225 meters, t = 5 seconds
Let's find an equation relating u and a in terms of d and using data given
Switching sides we get
Substituting values for t = 5, d = 225 we get
Multiplying both sides by 2 yields
We also have the formula:
where v is the current velocity and u the initial velocity
So
Multiply equation (2) by 5 and subtract from (1) to eliminate the a terms and solve for u