Asked by k
a 15kg rock falls from the top of a building 8.0 high. Find its PE and KE
a.when at rest at the top of the building
b. halfway down the ground
c. when it reaches the ground
d.speed when it reaches the ground
a.when at rest at the top of the building
b. halfway down the ground
c. when it reaches the ground
d.speed when it reaches the ground
Answers
Answered by
DonHo
a) when at rest
PE=mgh
h=8m
mgh = (15kg)(9.81m/s^2)(8m)=1177.2 J
KE = (1/2)*m*v^2
there is no velocity, v=0
so KE = 0J
b)
PE=(15kg)*(9.81m/s^2)(8/2m) = ?J
There is no KE while it's falling
KE = 0J
c) PE= m*g*h = (15)(9.81)(0) =0J
KE =(1/2)m*v^2
where v=sqrt(2*g*h)
= (2*9.81*8) = 12.53 m/s
KE = (1/2)*(15)*(156.96)^2 = ? J
d) speed when it reaches the ground:
v=12.53 m/s
To check:
PE_initial + KE_initial = PE_final + KE_final
1177.2J + 0J = 0J + 1177.2J
PE=mgh
h=8m
mgh = (15kg)(9.81m/s^2)(8m)=1177.2 J
KE = (1/2)*m*v^2
there is no velocity, v=0
so KE = 0J
b)
PE=(15kg)*(9.81m/s^2)(8/2m) = ?J
There is no KE while it's falling
KE = 0J
c) PE= m*g*h = (15)(9.81)(0) =0J
KE =(1/2)m*v^2
where v=sqrt(2*g*h)
= (2*9.81*8) = 12.53 m/s
KE = (1/2)*(15)*(156.96)^2 = ? J
d) speed when it reaches the ground:
v=12.53 m/s
To check:
PE_initial + KE_initial = PE_final + KE_final
1177.2J + 0J = 0J + 1177.2J
Answered by
DonHo
for part c), I made a typo:
KE = (1/2)*(15)*(12.53)^2 = 1177.2J
KE = (1/2)*(15)*(12.53)^2 = 1177.2J
Answered by
k
where did u get 12.53m/s
Answered by
Kupal
Taena niyo ayos para sa activity ko to sa school eh
Answered by
ako si dogie streamer
2 joints parang mafia
Answered by
Alfreddy
Control your temper so dont be angry
Answered by
Isko moreno
Vote me in the 2022 presidential elections!
Answered by
smile
mga kumukuha ng sagot diyan mga grade 11 hule kayoo
Answered by
smile
grade 12 pala nakopo hulee
Answered by
mama mo
ang gulo ng explanation pero okay lang haha
There are no AI answers yet. The ability to request AI answers is coming soon!
Submit Your Answer
We prioritize human answers over AI answers.
If you are human, and you can answer this question, please submit your answer.