SOLUTION: A hammer was dropped from a Carpenter's pocket from a height of 300 ft building and falls towards the earth in a straight line. a)What is the average velocity during the time it i

Question 1145938: A hammer was dropped from a Carpenter's pocket from a height of 300 ft building and falls towards the earth in a straight line.
a)What is the average velocity during the time it is falling.
b)What is the instantaneous velocity of the hammer when it hit the ground?
Found 3 solutions by rothauserc, ikleyn, Alan3354:
Answer by rothauserc(4718)   (Show Source): You can put this solution on YOUR website!
Since the height of the building is given in feet, we will use 32 feet per second squared as the acceleration of gravity
:
distance(s) = 0.5 * at^2, where a is acceleration of gravity and t is the time it takes for the hammer to hit the ground
:
0.5 * 32 * t^2 = 300
:
t^2 = 300/16 = 18.75
:
t = 4.33 seconds
:
(a) average velocity(v) = a/t = 32/4.33 = 7.39 feet/sec
:
(b) instantaneous velocity = at = 32 * 4.33 = 138.56 feet/sec
:
Answer by ikleyn(52786)   (Show Source): You can put this solution on YOUR website!
.

            The solution by tutor @rothauserc is not precisely correct, therefore I came to bring corrected solution.

Since the height of the building is given in feet, we will use 32 feet per second squared as the acceleration of gravity distance(s) = 0.5 * at^2, where a is acceleration of gravity and t is the time it takes for the hammer to hit the ground 0.5 * 32 * t^2 = 300 t^2 = 300/16 = 18.75 t = 4.33 seconds (a) average velocity(v) = = = 69.28 feet/sec <<<---=== my correction is in this line (b) instantaneous velocity = at = 32 * 4.33 = 138.56 feet/sec

Answer by Alan3354(69443)   (Show Source): You can put this solution on YOUR website!
A hammer was dropped from a Carpenter's pocket from a height of 300 ft building and falls towards the earth in a straight line.
a)What is the average velocity during the time it is falling.
b)What is the instantaneous velocity of the hammer when it hit the ground?
------------
h(t) = -16t^2 + 300
Impact is at h(t) = 0
-16t^2 + 300 = 0
t^2 = 300/16
t =~ 4.33 seconds
===============
acceleration = 32 ft/sec/sec
Speed at impact = 4.33*32 = 138.56 ft/sec
=========
Avg speed = 138.56/2 = 69.28 ft/sec
RELATED QUESTIONS
A hammer was dropped from the pocket of a constructor from a height of 288 ft building... (answered by Alan3354,ikleyn)
a hammer is dropped from a construction project 576 ft above the ground. the height h(in... (answered by Edwin McCravy)
The time =f(x), in seconds, for a free falling object to fall, x ft is modeled by f(x) = (answered by scott8148)
During the construction of a high-rise building, a worker accidentally dropped his... (answered by ikleyn)
a worker drops a hammer from the second-story roof that is 10 meters from the ground. if... (answered by scott8148)
A carpenter is building a wood frame. The height of the frame is 1 ft less than three... (answered by solver91311)
A ball ia dropped from top of 277 ft building. How many seconds till it hits ground if... (answered by Alan3354,josmiceli)
A building is 48 ft. tall. From the top of this building a ball is thrown straight up... (answered by funmath)
An object is dropped from rest at a height of 118 m. Find the distance it falls during... (answered by ikleyn)