Question

someone please help me with this acceleration problem...A truck travels at 40 m/s and slows down to 10 m/s in 5 seconds. What is the acceleration of the truck? Show formula

Answer 1

v = u + at
Here u = 40 m/s v = 10 m/s t= 5 s

Let acceleration = A
substitute

10 m/s = 40 m/s + A * 5 s
(10 - 40) m/s = A * 5 s
- 30 m/s = A * 5 s
(-30/5) m/s^2 = A

So A = -6 m/s^2
The negative sign shows that it is a negative acceleration ( as truck has solowed down).

Answer 2

acceleration = (final velocity - inicial velocity) / time
so:
a=10-40/5
a=-6m/s