Question
the dail 1.0 seconds after it is released? E6. A ball is dropped from a high building. Using the approxi- mate value of g = 10 m/s, find the change in velocity between the first and fifth seconds of its flight. A ball is thrown upward with an initial velocity of 14 Using the approximate value of g = 10 m/s2, what are the magnitude and direction of the ball's velocity a. 1 second after it is thrown? b. 2 seconds after it is thrown? El E7. E8. How high above the ground is the ball in exercise 7 a. 1 second after it is thrown? b. 2 seconds after it is thrown? E9. At what time does the ball in exercise 7 reach the high point cicht) (Use the approximate value of g = 10 m/s2,
Explanation / Answer
E6.
Initial velocity of the ball = vi=0m/s
We use kinematic eqn,
vf=vi-g*t
Velocity at 1st second,
vf1=vi-gt=0m/s – 10.0m/s^2*1.0s = -10.0 m/s
Velocity at 5th second,
vf5=vi-gt=0m/s – 10.0m/s^2*5.0s = -50.0 m/s
Change in velocity = vf5-vf1 = -50m/s – (-10.0m/s) = -40.0 m/s