Unformatted text preview: ease the most? If you drop a ball from a height of 4.9 m, it will hit the ground 1 s later. If you fire a bullet exactly horizontally from a height of 4.9 m, it will also hit the ground exactly 1 s later. Explain. If a golf ball and a bowling ball (when dropped from the same height) will hit your foot at the same speed, why does one hurt more than the other? Spring 2008 16 UCSD Physics 10 Doing the Numbers Imagine dropping an object, and measuring how fast it's moving over consecutive 1 second intervals The vertical component of velocity is changing by 9.8 m/s in each second, downwards Let's approximate this acceleration as 10 m/s2 Spring 2008 17 UCSD Physics 10 Starting from rest, letting go:
Time Interval Acceleration (m/s2 down) Vel. at end of interval (m/s down) After an interval t, the velocity changes by an amount at, so that vfinal = vinitial + at How fast was it going at the end of 3 sec? vinitial was 20 m/s after 2 sec a was 10 m/s (as always) t was 1 sec (interval)
vfinal = 20 m/s +...
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