Use conservation of momentum ;
m1u1 + m2u2 = m1v1 + m2v2
1200×15.6 + 0 = 2700v
v = 18720/2700
v = 6.933 or ~ 7 m/s
Answer:

Explanation:
As we know that mass is the product of volume and density
so we will have

here we have

so we will have

so we will have


now let the position of Pluto is at origin so we have




Answer: 12.44 millisecond
Explanation:
Based on the information given, to know the time taken for the impulse, which travels a distance of 1.58m to reach the brain will be:
Time taken = Distance/Speed
Time taken = 1.58/127
Time taken = 0.01244
Time taken = 12.44 millisecond.
Answer:
1.25 focal lengths
Explanation:
The lens equation states that:

where
f is the focal length
p is the object distance
q is the image distance
In this problem, the image is 4 times as far from the lens as is the object: this means that

If we substitute this into the lens equation and we rearrange it, we get

so, the object distance measured in focal lengths is
1.25 focal lenghts