A man holds a ballof weight 1/4Ib (1.11N) at rest in his hand. He then throws the ball vertically upward. In this process, his hand moves up 2ft(.06096m) and the ball leaves his hand with an upward velocity of 48ft/sec(14.63m/s). Find the applied force Fapp with which the man pushes the on the ball.
its pretty interesting but i cant figure it out.. if possible explain how you got your answer...Thank You!
2006-11-22 08:12:14 · 4 answers · asked by Alex M 1 in Science & Mathematics ➔ Physics
Equation:
V^2 = U^2 + 2 A (delX)
Then solve F = M A
where V = Final Velocity
U = Initial Velocity
A = Acceleration (unknown)
delX = distance of applied force (delX meaning delta X, or change in distance)
F = Force
M = Mass
Of course you have to consider two things:
The force applied over the two feet would have to be constant (this is an assumption you have to make to solve)
All your units are in ft and weight. you have to use the meters measurements and convert your ball's weight of 0.25 lb to kilograms (that's the mass measurement)
you now have more than enough information to solve this problem on your own.
NOTE: Jim, that is a horrible misuse of the wrong equations for solving this kind of problem. Nice try though.
2006-11-22 08:15:03 · answer #1 · answered by promethius9594 6 · 0⤊ 0⤋
it depends on what planet you are on.. the downward force from gravity on earth is 9.8 m/s/s, but is different on other planets, and would definitely have to be taken into account... in other words.. there is not sufficient information to solve the problem.. even if you take the question verbatim.. still his hand was being decelerated by planetary gravity for those two feet....unless he were standing on the wing of the shuttle in orbit....f=ma....the answer would be a vector between gravitational decelleration, and the upward accelleration of the hand, which cannot be determined unless we know the time it took the hand to move two feet, and the gravitational decelleration of the planet....f=m(v/t)...
the question gives the mass, the velocity, and the distance travelled by the hand, but there is no time given... im not surprised that you are stumped.. i am too
2006-11-22 16:41:18 · answer #2 · answered by luckily77777 2 · 0⤊ 0⤋
There's an error in the problem as given: 2ft and .06096m are not equivalent.
24 inches*1 m/39.37 inches = 0.6096m.
The method described by promethiu... should work well - just use the corrected data.
2006-11-22 18:05:10 · answer #3 · answered by sojsail 7 · 0⤊ 0⤋
Basically find the average acceleration. From that you can get the force via F = ma.
The acceleration is given from two equations:
distance travelled from rest = 1/2at^2.
acceleration a = change in vel/t = 14.63/t
So we have
.06096 = 1/2at^2
a = 14.63/t
two equations in two unkowns. So solve for a and t.
Then find force from ma = .25/2.2 a
2006-11-22 16:25:48 · answer #4 · answered by Jim C 3 · 0⤊ 1⤋