During the construction of a high-rise building, a worker accidentally dropped his portable electric screwdriver from a height of 144 ft. After t sec, the screwdriver had fallen a distance of ft. What was the velocity of the screwdriver at the time it hit the ground?
A) 12 ft/sec
B) 96 ft/sec
C) 768 ft/sec
D) 48 ft/sec

Question

During the construction of a high-rise building, a worker accidentally dropped his portable electric screwdriver from a height of 144 ft. After t sec, the screwdriver had fallen a distance of  ft. What was the velocity of the screwdriver at the time it hit the ground?
A) 12 ft/sec 
B) 96 ft/sec 
C) 768 ft/sec 
D) 48 ft/sec

Quizplus · Accepted Answer

Using the equation s = 16t^2 (where s is the distance fallen in feet and t is time in seconds), we can solve for t by setting s = 144 - 11eaa8b1_dc42_bb85_b1b6_63d3e3136e08_TB6026_11 = 126 ft:

126 = 16t^2
t^2 = 7.875
t = sqrt(7.875) seconds

Using the equation v = gt (where g is the acceleration due to gravity, approximately 32 ft/sec^2):

v = 32 x sqrt(7.875) = 96 ft/sec

Therefore, the velocity of the screwdriver at the time it hit the ground was 96 ft/sec.

During the Construction of a High-Rise Building, a Worker Accidentally