Answer:
Explanation:
For sound waves we have v=d/t where v is the speed of sound and d the distance between the astronauts, while for electromagnetic waves we have c=D/t where c is the speed of light and D the distance between the spaceship and Earth. <em>We have written both times as the same</em> because is what is imposed by the problem, so we have t=d/v=D/c, which means:
And for our values:
Answer:
Explanation:
1 )
We shall apply conservation of momentum law to solve the problem.
mv = ( M +m) V , m and M are masses of small and large object , v is the velocity of small object before collision and V is the velocity of both the objects together after collision .
.5 x .2 = (1.5 + .5)V
V = .05 m /s
2 ) We shall use formula for velocity of object after elastic collision as follows
v₁ =
m₁ and m₂ are masses of first and second object u₁ and u₂ are their initial velocity and v₁ and v₂ are their final velocity.
Putting the values
=
= - .66 m /s
Since the sign is negative so it will be in opposite direction .
Answer:
The wall is 680 meter away from the person.
Explanation:
Given data
Speed of sound = 340
Given that Persons said hello toward the opposite side she has an echo hello 4 seconds later means it takes 2 seconds for the sound to reach the wall & again 2 seconds to reach the persons ear.
Therefore the distance between the person & wall is
D = speed × Time
D = 340 × 2
D = 680 meter
Therefore the wall is 680 meter away from the person.