Given Information:
Elapsed time = t = 6 seconds
Required Information:
Distance = d = ?
Answer:
Distance = d = 2.058 km
Explanation:
We know that the speed of sound in the air is given by
v = 343 m/s
The relation between distance, speed and time is given by
distance = speed*time
substituting the given values yields,
distance = 343*6
distance = 2058 m
There are 1000 meters in 1 km so
d = 2058/1000
d = 2.058 km
Therefore, the storm is about 2.058 km away when elapse time between the lightning and the thunderclap is 6 seconds.
Answer:

Explanation:
The expression which represent the first diffraction minima by a circular aperture is given by
--------eqn 1
The angle through which the first minima is diffracted is given by
---------eqn 2
As
is very small so we can write 
So from eqn 1 and eqn 2 we can write
--------eqn 3
Here
is the position of first maxima D is the distance of screen from the circular aperture d is the diameter of aperture
It is given that diameter of circular aperture is 14.7 cm so 
Now putting all these value in eqn 3


Answer:
The resultant velocity is 
Explanation:
Apply the law of conservation of momentum

Where
is the mass of the Luxury Liner = 40,000 ton
is the velocity of Luxury Liner = 20 knots due west
mass of freighter = 60,000
is the velocity of freighter = 10 knots due north
Apply the law of conservation of momentum toward the the west direction

So the equation would be

Substituting values

Where
the final velocity due west
Making
the subject


Apply the law of conservation of momentum toward the the north direction

So the equation would be

Where
the final velocity due north
Making
the subject


The resultant velocity is


