Answer:


Explanation:
(a)
Given:
- mass of comet,

- velocity of the comet,

<u>Now, the kinetic energy of the comet can be given by:</u>



(b)
Given:
- energy released by 1 megaton of TNT,

<u>Now the kinetic energy of the comet in terms of energy of 1 megaton TNT:</u>

i.e.

Initial speed is less than final speed
<span>The work output of a machine divided by the work input is the "Efficiency" of the machine.
Hope this helps!</span>
Answer:1.55 times
Explanation:
Given
First wavelength
Second wavelength
According wien's diplacement law

where 
T=Temperature
Let
be the temperatures corresponding to
respectively.



Thus object with
is 1.55 times hotter than object with wavelength 
Answer:
Check the explanation
Explanation:
1) Pressure acting on the plug = Patm + P
Pressure = Patm + rho*g*h (Here h = D2)
Pressure = 101325 + 1000*9.8*7
Pressure = 169925 Pa
so, Force = PA
Force = 169925*pi*0.0152
Force = 120.1 N