Answer:
B) (-2.0 m, 0.0 m)
Explanation:
Given:
Mass of particle 1 is, 
Mass of particle 2 is, 
Position of center of mass is, 
Position of particle 1 is, 
Position of particle 2 is, 
We know that, the x-coordinate of center of mass of two particles is given as:

Plug in the values given.

We know that, the y-coordinate of center of mass of two particles is given as:

Plug in the values given.

Therefore, the position of particle 2 of mass 3.0 kg is (-2.0 m, 0.0 m).
So, option (B) is correct.
Answer:
Explanation:
Time dilation formula is
T = T₀ / √ 1-v²/c²
T₀ is time elapsed in moving reference , T time elapsed in stationary reference.
Here T₀ = 1 second
T = 1/√ 1-0.9² = 1/.4358 = 2.3 second
So 2.3 second will pass for each second on moving reference.
Answer:
(a) 7 m
(b) 1 m
Explanation:
Given:
The magnitude of displacement vector 'a' is 3 m
The magnitude of displacement vector 'b' is 4 m.
The vector 'c' is the vector sum of vectors 'a' and 'b'.
(a)
Now, when the angle between the vectors is 0°, it means that the vectors are in the same direction. When vectors are in the same direction, then their resultant magnitude is simply the sum of their magnitudes.
So, magnitude of 'c' when 'a' and 'b' are in same direction is given as:

Therefore, the magnitude of vector 'c' is 7 m when angle between 'a' and 'b' is 0°.
(b)
When the angle between the vectors is 180°, it means that the vectors are exactly in the opposite direction. When the vectors are in opposite direction, then their resultant magnitude is the subtraction of their magnitudes.
So, magnitude of 'c' when 'a' and 'b' are in opposite direction is:

Therefore, the magnitude of vector 'c' is 1 m when angle between 'a' and 'b' is 180°.
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