Answer:
The objects can be distinguished by their weight instead of by mass.
Explanation
Because mass is constant, the two objects cannot be distinguished by mass.
However, gravitational acceleration varies in outer space. Therefore the heavier mass will register a higher reading on a weighing scale.
Note that an object of mass M weighs Mg, where g = acceleration due to gravity.
Explanation:
The scanner records the time from when a ultrasound wave is emitted to when its reflection is received. A technician calculates the depth of the reflection using the equation as :

The distance covered by ultrasonic wave when it was emitted and gets reflected is 2d. Speed is given by :

d is distance and t is time
Here, d = 2d
So, the factor of (1/2) is used because the distance covered by the wave is 2 times when it was emitted and received.
Answer:
The index of refraction of the liquid is 1.35.
Explanation:
It is given that,
Critical angle for a certain air-liquid surface, 
Let n₁ is the refractive index of liquid and n₂ is the refractive index of air, n₂ =1
Using Snell's law for air liquid interface as :




So, the index of refraction of the liquid is 1.35. Hence, this is the required solution.
I dont think so. It also probably matters what type of str it is