Question

a 150 - kg object takes 90 seconds to travel a 2,500 - meter straight path. it begins the trip traveling 120 meters per second and decelerates to a velocity of 20 meters per second.
what was its acceleration?

• 1.11 m/s²
• 0.3 m/s²

+ 1.11 m/s²
+ 80 m/s²

Explanation:

Step1: Recall the acceleration formula

Acceleration \(a=\frac{v - u}{t}\), where \(v\) is final velocity, \(u\) is initial velocity, \(t\) is time.

Step2: Substitute the values

Given \(u = 120\space m/s\), \(v=20\space m/s\), \(t = 90\space s\).
\(a=\frac{20 - 120}{90}=\frac{- 100}{90}\approx - 1.11\space m/s^{2}\)

Answer:

\(-1.11\space m/s^{2}\)