Which of these is the correct no-time kinematic equation?
Here is the van from the no-time equation again: in at 7 m/s, accelerating at 3 m/s² over 20 m of road. How fast is it moving at the end of the stretch? Follow the same steps you've used when solving with other equations in the past.
1. Write down the values in the question, and mark the unknown.
2. Write down the equation.
3. Substitute in the values.
A motorcycle moving at 5 m/s accelerates at 4 m/s² while covering 18 m. What is its final speed?
Write down the values in the question:
v₀ = 5 m/s
a = 4 m/s²
Δx = 18 m
Write down the equation, substitute in the values, and simplify:
v² = v₀² + 2aΔx
v² = 5² + (2)(4)(18)
v² = 25 + 144
v² = 169
Find v — square root both sides:
v = √169
The root gives the size of the velocity. The motorcycle keeps moving forward, so the velocity is positive:
v = 13 m/s
A car merging onto a highway is moving at 9 m/s and accelerates at 4 m/s² while covering 18 m. What is its final speed, in m/s? Enter the number only.
On the way home, the van brakes: traveling at 12 m/s, it accelerates at −2 m/s² for 27 m of road. What is its speed at the end of that stretch?
Write down the values in the question:
v₀ = 12 m/s
a = −2 m/s²
Δx = 27 m
Write down the equation, substitute in the values, and simplify:
v² = v₀² + 2aΔx
v² = 12² + (2)(−2)(27)
v² = 144 − 108
v² = 36
Find v — square root both sides:
v = √36
v = 6 m/s
A truck moving at 15 m/s brakes at −4 m/s² while covering 22 m. What is its speed at the end of that stretch, in m/s? Enter the number only.
Back on the 20 m stretch: the van leaves it at 13 m/s — and nobody ever needed a stopwatch.
A sports car moving at 11 m/s accelerates at 4 m/s² while covering 30 m. What is its final speed, in m/s? Enter the number only.
A car moving at 25 m/s brakes hard at −6 m/s² while covering 50 m. What is its speed at the end of the braking stretch, in m/s? Enter the number only.
A car on an entrance ramp is moving at 10 m/s and accelerates at 3 m/s² over the ramp's remaining 50 m. What is its speed when it leaves the ramp, in m/s? Enter the number only.