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supernova1203
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Homework Statement
Marian who is standing on her balcony is surprised by a pigeon, and throws a flowerpot up, in the air at 2.1 m/s. It takes a total of 3 s for the flowerpot to smash to the ground. The flowerpot experiences acceleration due to gravity of 9.8m/s
a) How high is Marians balcony?
b)How fast was the flowerpot moving just before it smashed into the ground?
Homework Equations
Δd=V1Δt + 1/2 aΔt^2
V2=V1+aΔt
Δd=V1Δt - 1/2 aΔt^2
(By the way id like to know what this third equation is for, when is it appropriate to use it? I know when to use it when i see a v-t graph and am required to find displacement, and geometrically there are 2 objects in graph, i have to find area, of one and to do so would require me to subtract the area from other geometrical object, in such a scenario i would use the 3rd equation, but if the quest is in written word problem format, i don't know when to use the 3rd formula.)
The Attempt at a Solution
a) v=2.1m/s
Δt=3 s
a=-9.8m/s
Δd=V1Δt + 1/2 aΔt^2
=(2.1)(3)+1/2(-9.81)(3)^2
=6.3+1/2(-9.81)(9)
=6.3+1/2-88.79
=6.3-44.14
Δd=-37.82m
b) v1=2.1m/s
Δt=3s
a=-9.8m/s
v2=v1+aΔt
=2.1+(-9.8)(3)
V2=-27.3 m/s
Do these answers/solutions make sense?