Explanation:
Only few supernova are observed in our galaxy -
Type II supernovae ( i.e. the explosions of the massive stars ) occurred in the Milky Way, and they might be hidden by the intervening dust if they are located in the more distant parts of our Galaxy .
Type Ia supernovae , which need a white dwarf star in the binary star system , are brighter than the type II supernovae , but some of them could also happen in the older parts of Galaxy which are hidden due to the buildup of the dust and gas .
Since 1 examiner = 10^18miner
then 10^10miners =10^(10-18)=10^-8examiner
The guy below is wrong!
F=ma
Where force = mass x acceleration
We dont have acceleration, a= change in velocity divided by the time taken.
a = v (final velocity) - u (initial) / t
a us 8-0 (at rest means u was 0) / 20 = 0.4
Using F=ma
F= mass x acceleration
F= 4 x 0.4
F=1.6 N
Answer: a) Moment = 200N.m
b) F = 500N
Explanation: <u>Moment</u> or <u>Torque</u> is the tendency of a body to rotate because of an aplplied force. It can be calculated as
F is force applied
r is distance from the force to the point of rotation
θ is the angle formed between force and distance
a) Since F and r are perpendicular, θ=90°, sin90° = 1, so
200
<u>Torque</u><u> caused by weight of the barrier at the pivot is </u><u>200N.m</u>
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b) Counterweight has the same torque as pivot: 200
So, to find Force necessary to balance the weight:
F = 500
<u>It is necessary </u><u>a force of 500N</u><u> from the counterweight to balance the weight.</u>
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