A 8.50 kg steel ball is dropped from a platform 15.3 meters above the ground.?

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A 8.50 kg steel ball is dropped from a platform 15.3 meters above the ground.?

a. Find the kinetic energy of the ball when it hits the ground.
b. What is the speed of the ball when its hits the ground?

2007-01-31 05:08:05 · 3 answers · asked by nkh0003 1 in Science & Mathematics ➔ Physics

3 answers

Kinetic energy Ek is equal to the loss of potential energy Ep

Ek = Ep = mgh = 8.5kg * 9.8m/s^2 * 15.3m = 1274.5 J

The speed is given by
Ek = 1/2 mv^2
v = sqrt(2Ek/m) = sqrt(2*1274.5/8.5) = 17.3 m/s

2007-01-31 05:15:00 · answer #1 · answered by catarthur 6 · 0⤊ 0⤋

x = 1/2at^2
t^2 = 15.3/4,9
t = 1.77 sec

v = at = 9.8*1.76 = 17.3 m/sec

KE = 1/2m*v^2 = 0.5*8.5*17.3^2 =1280 J

Don't forget your significant figures!

2007-01-31 13:15:18 · answer #2 · answered by gebobs 6 · 0⤊ 0⤋

Why did you drop it?

2007-01-31 13:12:47 · answer #3 · answered by Bob 3 · 0⤊ 0⤋