How long does it take for a 1000kg object to fall 45m? (Ignore air resistance and assume constant acceleration from gravity of -10m/sec2)
A) 0.045 seconds
B) 3 seconds
C) 4.5 seconds
D) 9 seconds
Mass does not affect time for a projectile to fall in constant gravitational acceleration. For a 45m fall, use the equation y = v0t+1/2at2, with y = 45m, v0 = 0m/sec, and a = 10m/sec2.
45m = 1/2*(10m/sec2)t2, 9sec2 = t2, t = 3 seconds.
A) 0.045 seconds, incorrect, This answer divides the distance by the mass.
B) 3 seconds, correct.
C) 4.5 seconds, incorrect, This answer divides the distance by the gravitational acceleration.
D) 9 seconds, incorrect, This answer uses an incorrect formula proportional to t rather than t2.