Before going to answer this question first we have to know the fundamental principle of magnetism.
A magnet have two poles .The important characteristic of a magnet is that like poles will repel each other while unlike poles will attract each other.
Through this concept the question can be answered as explained below-
A-As per first option the side of magnet A is repelled by the south pole of magnet B. Hence the pole of a must be south .It can't be north as it will lead to attraction.
B-The side of magnet A is repelled by the north pole of magnet B. Hence the side of A must be north pole.It can't be a south pole.
C-The side of magnet A is attracted by the south pole of magnet B .Hence the side of magnet A must be north.Hence this is right
D-The side of magnet A is attracted by the north pole of magnet B. Hence the side of A must south.It can't be north as it will lead to repulsion.
Hence the option C is right.
Answer:
Option (B)
Explanation:
According to Hubble's law, the distance from the earth to the distant galaxies is directly proportional to their recessional velocity (redshift). This means that the more is the distance between the earth and a galaxy, the faster the galaxy is moving away from the earth.
Recessional velocity normally refers to the speed or velocity at which any astronomical body such as a planet, asteroid, star or galaxy moves away from a reference point, such as from earth.
Thus, the correct answer is option (B).
Answer:
10.77kgm/s
Explanation:
Impulse is defined as change in momentum of a body.
From Newton's second law
F = ma
F = m(v-u)/t
Ft = m(v-u) = Impulse
where;
M is the mass of the object
v is the final velocity of the object
u is the initial velocity of the object.
Using the formula to time the impulse
Impulse = m(v-u)
m = 0.745kg
Since the ball dropped from rest at a height of 3.75m, it's initial velocity can be calculated according to the equation of motion
g is positive (since it dropped from a height I.e downward motion)
v²= u²+2gH
v² = 0²+2(9.8)(3.75)
v² = 73.5
v = √73.5
v = 8.57m/s(initial velocity of the ball)
If the ball rebounds to a height if 1.78m, g will be negative (since it is an upward motion)
In this case
v² = u²-2gH
0² = u²-2(9.8)(1.78)
-u² = -34.89
u = √34.89
u = 5.91m/s (final velocity of the ball)
Impulse = 0.745(5.91-(-8.57))
Impulse = 0.745(5.91+8.57)
Impulse = 0.745(14.48)
Impulse = 10.77kgm/s
Note that the initial velocity was negated while calculating impulse due to rebounce.
Answer:
Water with a pH of five is ten times more acidic than water having a pH of six. As this diagram shows, pH ranges from 0 to 14, with 7 being neutral. pHs less than 7 are acidic while pHs greater than 7 are alkaline (basic).
Explanation:
