10.if zak is traveling at a velocity of 34.8 m/s and he increases his speed to 214.3 m/s over 20
seconds, what is his acceleration?

8.975 m/

Explanation:

Travel starting velocity (u) = 34.8 m/s

Achieved (final) velocity = 214.3 m/s

Travelling time(t) = 20 s  

we know that, v =u +at

                          ; where v= final velocity

                                       u=start velocity

                                       a=acceleration

                                       t=time

Therefore,

       His acceleration,     a = (v-u)/t

                                           =(214.3-34.8)/20

                                           = 8.975 m/

acceleration = (change in speed) / (time for the change)

change in speed = (20-120)= -100 m/s.

1.5 min = 90 sec

acceleration = -100/90 = -1.11 m/s^2.

we don't care about the 150kg or the 2,500 meters. they don't make any difference.

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not moving. pos accel,