A projectile is shot almost vertically upwards from the edge of a tall building. It takes 22 seconds to reach the ground at the foot of the building. A stone dropped from the building takes 5.6 seconds to reach the ground. What is the initial velocity of the projectile?
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Help with Projectile Motions please (2 Viewers)
- Thread starter ThreeOne
- Start date
From the stone you get
(delta)y=ut+0.5at^2
(delta)y=0+0.5 * –9.8 * 5.6^2
(delta)y=-153.66
therefore the building is 153.66m high
subbing into (delta)y=ut+0.5at^2
-153.66=u * 22 + 0.5 * -9.8 * 22^2
manipulating you get u=100.81 m/s
i think this is right
(delta)y=ut+0.5at^2
(delta)y=0+0.5 * –9.8 * 5.6^2
(delta)y=-153.66
therefore the building is 153.66m high
subbing into (delta)y=ut+0.5at^2
-153.66=u * 22 + 0.5 * -9.8 * 22^2
manipulating you get u=100.81 m/s
i think this is right
Denoz is right
It may be worth noting though that rounding midway through the question can cause innacuracies.
From rounding to 153.66 rather than keeping as 153.664 the final answer is different by .01
I got 100.815 m/s which rounds to 100.82 ... depending on the exam this may cost marks.
It may be worth noting though that rounding midway through the question can cause innacuracies.
From rounding to 153.66 rather than keeping as 153.664 the final answer is different by .01
I got 100.815 m/s which rounds to 100.82 ... depending on the exam this may cost marks.