volume_mute
An object falling from rest
publish date: 2022/08/06 01:25:00 GMT+10
volume_muteAn object falling from rest reaches a speed of ft/s (or m/s) after falling 5 seconds. (Ignore air resistance.) At this time it has fallen ft (or m).
Correct Answer
(1) 160
(2) 49
(3) 400
(4) 122.5
Explanation
Calculate the final speed by multiplying 5 by acceleration
s = t * a = 5 * a
Calculate the total distance by this equation
d = 1/2 at2
Ft | Meter | |
speed | 5*9.8 = 49 | 32 * 5 = 160 |
distance | 1/2 * 9.8 * 52 = 122.5 | 1/2 * 32 * 52 = 400 |
Reference
Basic Physics: A Self-Teaching Guide