A pendulum has 711 J of potential energy at the highest point of its swing. How much kinetic energy will it have at the bottom o
f its swing? ______ Joules......I would prefer an explanation on how the answer was obtained.
I figured it out!!!!
PE=KE soooo
711 J of PE = 711 J of KE
I figured it out!!!!
PE=KE soooo
711 J of PE = 711 J of KE
1 answer:
According to law of conservation of energy,
<span>Energy can neither be constructed nor be destroyed but can be transformed from one form to another.
</span>
<span>At the highest point of the pendulum(point b), pendulum is associated with potential energy only and no kinetic energy.
</span><span>Therefore total energy at point b = potential energy = 711 J.... i
</span>
<span>At the bottom most point(point a), pendulum is associated only with kinetic energy and no potential energy.
</span>Therefore total energy at point a = kinetic energy ---- ii
<span>From i and ii,
</span>Kinetic energy = potential energy = 711 J.(Conserving energy)
Hence kinetic energy at the bottom most point is 711 J.
Hope this helps!!
<span>Energy can neither be constructed nor be destroyed but can be transformed from one form to another.
</span>
<span>At the highest point of the pendulum(point b), pendulum is associated with potential energy only and no kinetic energy.
</span><span>Therefore total energy at point b = potential energy = 711 J.... i
</span>
<span>At the bottom most point(point a), pendulum is associated only with kinetic energy and no potential energy.
</span>Therefore total energy at point a = kinetic energy ---- ii
<span>From i and ii,
</span>Kinetic energy = potential energy = 711 J.(Conserving energy)
Hence kinetic energy at the bottom most point is 711 J.
Hope this helps!!
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Answer:
Explanation:
Part A) Using
light intensity I= P/A
A= Area= π (Radius)^2= π((0.67*10^-6m)/(2))^2= 1.12*10^-13 m^2
Radius= Diameter/2
P= power= 10*10^-3=0.01 W
light intensity I= 0.01/(1.12*10^-13)= 9*10^10 W/m^2
Part B) Using
I=c*ε*E^2/2
rearrange to solve for E= ((I*2)/(c*ε))
c is the speed of light which is 3*10^8 m/s^2
ε=permittivity of free space or dielectric constant= 8.85* 10^-12 F⋅m−1
I= the already solved light intensity= 8.85*10^10 W/m^2
amplitude of the electric field E= (9*10^10 W/m^2)*(2) / (3*10^8 m/s^2)*(8.85* 10^-12 F⋅m−1)
---> E= (1.8*10^11) / (2.66*10^-3) =
(6.8*10^13) = 8.25*10^6 V/m
Answer:
(a)
(b)
(c) K.E. = 21.168 J
(d)
Explanation:
Given:
- mass of a block, M = 3.6 kg
- initial velocity of the block,
- constant downward acceleration,
That a constant upward acceleration of
is applied in the presence of gravity.
∴
- height through which the block falls, d = 4.2 m
(a)
Force by the cord on the block,
∴Work by the cord on the block,
We take -ve sign because the direction of force and the displacement are opposite to each other.
(b)
Force on the block due to gravity:
∵the gravity is naturally a constant and we cannot change it
∴Work by the gravity on the block,
(c)
Kinetic energy of the block will be equal to the net work done i.e. sum of the two works.
mathematically:
K.E. = 21.168 J
(d)
From the equation of motion:
putting the respective values:
is the speed when the block has fallen 4.2 meters.