- An object with an initial velocity of 4 m/s moves along a
straight axis under constant acceleration. Three seconds later, its
velocity is 14 m/s. How far did it travel during this time?
Here’s How to Crack It
We’re given v 0 , t, and v, and we’re asked for ∆s. So a is missing; it isn’t given and
it isn’t asked for, so we use Big Five #1.
∆s = vt = (v 0 + v)t = (4 m/s + 14 m/s)(3 s) = 27 m
- A car that’s initially traveling at 10 m/s accelerates uniformly
for 4 seconds at a rate of 2 m/s^2 n a straight line. How far does the
car travel during this time?
Here’s How to Crack It
We’re given v 0 , t, and a, and we’re asked for s. So v is missing; it isn’t given and it
isn’t asked for, so we use Big Five #2.
∆s = v 0 ∆t = (at^2 = (10 m/s)(4s) + (2 m/s^2 )(4 s)^2 = 56 m