Answer:
Pu - 239 have the smaller critical mass.
Explanation:
Critical mass is the smallest amount of certain element of mass that is needed to achieve a nuclear chain reaction early . Since Pu - 239 releases an average of 2.7 neutrons per fission as compared to U - 235 that releases 2.5 neutrons per fission. So, Pu - 239 has smaller critical mass, because Pu - 239 has a higher probability for fission and produces a large no. of neutrons per fission event. Infact of all the basic nuclear fuels, Pu - 239 has smallest critical mass. Critical mass depends on the nuclear properties of elements undergoing fission reaction. Hence, as Pu - 239 produces large no. of neutrons per fission than U - 235 and Pu - 239 has smaller critical mass.
Answer:
26.4 m/s
Explanation:
4 g = 0.004 kg
By the law of momentum conservation, the momentum before and after the impact must be the same



So the speed of the block after the impact is 26.4 m/s
Answer:
Workdone = 147Nm
Explanation:
Given the following data;
Mass = 5kg
Height = 3m
We know that acceleration due to gravity is 9.8m/s²
First of all, we would find the force applied;
Force = 5*9.8
Force = 49N
Now, to find the workdone;
Substituting into the equation, we have;
Workdone = 49 * 3
Workdone = 147Nm
Answer:
5 N
Explanation:
The bucket is moving at a constant speed of 2m/s Therefore F=ma is 0 N for this to be correct the magnitude of the force exerted by the rope must be equal to the weight of the bucket which is 5 N
Answer:
The convex lens is shaped so that all light rays that enter it parallel to its axis cross one another at a single point on the opposite side of the lens.
Explanation: