Question

Rakesh fires a gun 160 m from a cliff. Ashok who
is standing 320 m further away from the cliff hears
the gunshot (1) second after he sees the flash.
Ashok and Rakesh will hear the echo from the cliff
(11) second and (111) second respectively after
(iv) the (V)
Speed of sound = 320 m/s (approximate)
and speed of light = 3 x 108 m/s
my Cliff
Mk 160 mx 320 m
Ashok
Rakesh
A.
B.
C.
D.
(i)
1
1
2
1
(ii)
2
2
1
1.5
(iii)
1
1
2
1
(iv) (v)
Seeing Flash
Hearing Gunshot
Hearing Gunshot
Seeing Flash​

Answer 1

Explanation:

Given Rakesh fires a gun 160 m from a cliff. Ashok who  is standing 320 m further away from the cliff hears  the gunshot (1) second after he sees the flash.  Ashok and Rakesh will hear the echo from the cliff

Distance between two person = 320 m

Time after which he heard the sound = 1 s

So speed = distance / time = 320 m / s

Now time to hear the echo = total distance travelled / speed

So total distance = 160 + 160 + 320 = 640 m (since person A to cliff then back to person A + distance from person A to person)

Time for hearing echo will be 640 / 320 = 2 secs

Answer 2

Answer:

answer b is correct answer