Since the lady is capable of delivering 2 strokes in 1 second, we know that it takes 0.5 seconds for one stroke of the hammer.
It is given that one more blow is heard even after she is seen as stopping hammering. This means that the sound from the last blow reached us a little later: 0.5 seconds after the last blow.
So, we know that time taken for the sound from the last blow to reach us t = 0.5 s
Speed of Sound is given as V = 340 m/s
Distance of the lady from us D = ?
Using the equation D = V.t, we get D = (340)(0.5) = 170 m
Thus, we can understand that the lady is 170 meters away from us.
I think it is C , idk why, but I just learn about this and I think it is.... sorry I didn't really help.....
Answer:
2.4 m/s
Explanation:
Given:
Velocity of the object moving north = 2.1 m/s
Velocity of the river moving eastward = 1.2 m/s
The resultant velocity is the vector sum of the velocities of object and river.
Since the directions of velocity of object and river are perpendicular to each other, the magnitude of the resultant velocity is obtained using Pythagoras Theorem.
The velocities are the legs of the right angled triangle and the resultant velocity is the hypotenuse.
The magnitude of the resultant velocity (R) is given as:

Therefore, the resultant velocity has a magnitude of 2.4 m/s.
The answer is the Second one