Answer:
<h2>FOCAL</h2>
Explanation:
<em>The center of a lens is known as its optical center. </em><em>All light rays incident on a particular lens converges at a points a point known as the principal focus or the focal point after reflecting</em><em>. Note that all light incident on a reflecting surface must all converge at this focal point after reflection. </em>
The distance measured from the center of this lens to its principal focus (otherwise known as focal point) is known as the <em>focal length of the lens. </em>
<em>Based on the explanation above, it cam be concluded that the distance from the center of a lens to the location where parallel rays converge or appear to converge is called the</em><em> FOCAL</em><em> length.</em>
Answer:
the energy absorbed is 4.477 x 10⁶ J
Explanation:
mass of the liquid, m = 13 kg
initial temperature of the liquid, t₁ = 18 ⁰C
final temperature of the liquid, t₂ = 100 ⁰C
specific heat capacity of water, c = 4,200 J/kg⁰C
The energy absorbed is calculated as;
H = mcΔt
H = mc(t₂ - t₁)
H = 13 x 4,200(100 - 18)
H = 4.477 x 10⁶ J
Therefore, the energy absorbed is 4.477 x 10⁶ J
Answer: 11369.46 m/s
Explanation:
We have the following data:
is the mass of the bowling ball
is the velocity of the bowling ball
is the mass of the ping-pong ball
is the velocity of the ping-pong ball
Now, the momentum
of the bowling ball is:
(1)
(2)
And the momentum
of the ping-pong ball is:
(3)
If the momentum of the bowling ball is equal to the momentum of the ping-pong ball:
(4)
(5)
Isolating
:
(6)
(7)
Finally:
![V_{2}=11369.46 m/s](https://tex.z-dn.net/?f=V_%7B2%7D%3D11369.46%20m%2Fs)
Answer:
(a) 2.5 m/s
(b) 37.5 KJ
Explanation:
(a)
From the law of conservation of momentum, Initial momentum=Final momentum
![mV_1+3mV_2=(m+3m)V_f=4mV_f](https://tex.z-dn.net/?f=mV_1%2B3mV_2%3D%28m%2B3m%29V_f%3D4mV_f)
and making
the subject then
and since
is initial velocity of car, value given as 4 m/s,
is the initial velocity of the three cars stuck together, value given as 2 m/s and
is the final velocity which is unknown. By substitution
![V_f=\frac {4+(3\times2)}{4}=2.5 m/s](https://tex.z-dn.net/?f=V_f%3D%5Cfrac%20%7B4%2B%283%5Ctimes2%29%7D%7B4%7D%3D2.5%20m%2Fs)
(b)
Initial kinetic energy is given by
![\frac {mV_1^{2}}{2}+\frac {3mV_2^{2}}{2}=\frac {m(V_1^{2}+3V_2^{2}}{2}=\frac {2.5\times 10^{4}(4^{2}+3(2^{2}))}{2}=350\times10^{3} J= 350 KJ](https://tex.z-dn.net/?f=%5Cfrac%20%7BmV_1%5E%7B2%7D%7D%7B2%7D%2B%5Cfrac%20%7B3mV_2%5E%7B2%7D%7D%7B2%7D%3D%5Cfrac%20%7Bm%28V_1%5E%7B2%7D%2B3V_2%5E%7B2%7D%7D%7B2%7D%3D%5Cfrac%20%7B2.5%5Ctimes%2010%5E%7B4%7D%284%5E%7B2%7D%2B3%282%5E%7B2%7D%29%29%7D%7B2%7D%3D350%5Ctimes10%5E%7B3%7D%20J%3D%20350%20KJ)
Final kinetic energy is given by
![\frac {4mV_f^{2}}{2}=\frac {4\times 2.5\times 10^{4}\times 2.5^{2}}{2}=312.5\times 10^{3} J=312.5 KJ](https://tex.z-dn.net/?f=%5Cfrac%20%7B4mV_f%5E%7B2%7D%7D%7B2%7D%3D%5Cfrac%20%7B4%5Ctimes%202.5%5Ctimes%2010%5E%7B4%7D%5Ctimes%202.5%5E%7B2%7D%7D%7B2%7D%3D312.5%5Ctimes%2010%5E%7B3%7D%20J%3D312.5%20KJ)
The energy lost is given by subtracting the final kinetic energy from the initial kinetic energy hence
Energy lost=350-312.5=37.5 KJ