The focal length would likely decrease as the refractive index and the increase when the curvature radius of the lens increases. The decrease in focal length happens since a higher index of refraction would signify that the rays of the sun striking to an object would tend to bend more.
Answer:
Distance of the object is 8.6 m
Explanation:
As we know that the speed of sound at t degree C is given as

here we know that the temperature is
t = 20 degree C
so we have


now we know that bat heard the echo of sound in 0.05 s
so the to and fro distance of the object is d + d = 2d
so we have



Answer:

Given:
Initial velocity (u) = 0 m/s
Final velocity (v) = 44 m/s
Acceleration (a) = 5 m/s²
To Find:
Time taken (t)
Explanation:
From equation of motion we have:

By substituting value of u, v & a in the equation we get:

Answer:
Distance of metal fragment is 0.0975 m
Explanation:
As we know that the ultrasound will move towards the metal fragment and reflected back to the transducer
So the time interval in which sound will go to the metal fragment and come back is given as

now we know that the speed of the wave in the metal is
v = 1300 m/s
now we know that total distance traveled by the ultrasonic wave is given as



so the depth of metal fragment is half of total distance because in the ultraviolet sound move to and from between transducer and metal fragment so its distance is given as

