Question

Superman is flying and slows from a velocity 60 m/s to a velocity of 30 m/s in 300m. What is his acceleration?

а
-0.1 m/s/s
-4.5m/s/s
b
-9m/s/s
d
-1.0m/s/s

Answer 1

a = - 4.5 [m/s²]

Step-by-step explanation:

To solve this problem we must use the following equation of kinematics.

`v_(f)^(2)= v_(o)^(2)+2*a*x`

where:

Vf = final velocity = 30 [m/s]

Vo = initial velocity = 60 [m/s]

x = distance = 300 [m]

a = acceleration [m/s²]

Now replacing:

`30^(2) = 60^(2)+2*a*300\\30^(2) -60^(2)=600*a\\-2700 = 600*a\\a=-4.5[m/s^(2) ]`