Complete Question
The complete question is shown on the first and second uploaded image
Answer:
The velocity is
Explanation:
The kinetic energy of the 9 kg can be determined by these expression
Kinetic energy of 9 kg block = initial energy stored - energy lost as a result of friction
Now to obtain the initial energy stored
Let U denote the initial energy stored and

Where x is the length the spring is displaced
k is the force constant of the string


Now referring to the formula above
i.e Kinetic energy of 9 kg block = initial energy stored - energy lost as a result of friction



and we are told that coefficient of friction = 0.4 and the mass is 9 kg ,the acceleration due to gravity
this displacement length of spring = 0.6
Therefore 
Answer:
E=h.f
=5.2×1014×6.63×10^-34
E=3.496×10^-30 J
Answer:
hi is
Explanation:
Ans. (1) For preparing vaccines, in olden days,microbes were injected in the bodies of horses ormonkeys. These laboratory animals used to makeantibodies to defend these microbes. Antibodies areproteins which can act against the disease-causinggerms. These antibodies were extracted from theblood of these animals and were used as vaccines.(2) Now-a-days with the advent of biotechnology,the vaccines are manufactured in laboratories withthe help of bacteria. For this purpose, a detailedstudy of the disease causing germ is undertaken.The genes and the DNA of such microbes arethoroughly explored. Then based on thisinformation, proteins which can act against suchmicrobes are synthetically prepared in thelaboratories. The safe vaccine is produced in such away which can defend the body against infections.3) Some types of vaccines are prepared from theextracts of germs. These germs or microbes aredeactivated and made dormant. When they areinjected in the body of a person, they initiate thedefending action. The body of such vaccinatedperson, already develops the antibodies in his or herbody. When in future, this person is again attackedby similar germs the defence starts immediately andthe person does not become sick.
Answer: 2120 N is correct
Explanation: correct answer for acellus
this has something to do with black body radiation and absorption