Answer:
option E
Explanation:
given,
diameter = 4 mm
shutter speed = 1/1000 s
diameter of aperture = ?
shutter speed = 1/250 s
exposure time to the shutter time
N is the diameter of the aperture and t is the time of exposure
now,
inserting all the values
N₂² = 4
N₂ = 2 mm
hence , the correct answer is option E
Answer:
10.01 cm
Explanation:
Given that,
The time delay between transmission and the arrival of the reflected wave of a signal using ultrasound traveling through a piece of fat tissue was 0.13 ms.
The average propagation speed for sound in body tissue is 1540 m/s.
We need to find the depth when the reflection occur. We know that, the distance is double when transmitting and arriving. So,
or
d = 10.01 cm
So, the reflection will occur at 10.01 cm.
Answer:
2000 kg m/s
Explanation:
The momentum of an object is a vector quantity whose magnitude is given by
where
m is the mass of the object
v is the velocity of the object
and its direction is the same as the velocity.
In this problem, we have:
- Spaceship 1 has
m = 200 kg (mass)
v = 0 m/s (zero velocity)
So its momentum is
- Spaceship 2 has
m = 200 kg (mass)
v = 10 m/s (velocity)
So its momentum is
Therefore, the combined momentum of the two spaceships is