Explanation:
Following are two interactions that are generally involved when we use a TV remote control to change the channel :
1. Figure touches remote buttons, and its a short range interaction.
2. Now remote sends signal to Television, this is a long range interaction.
Answer:
Systematic errors.
Explanation:
The density of the aluminium was calculated by a human and this is not natural but can be due to errors in the calibration of the scale for measuring the weight or taking readings from the measuring cylinder.
Random errors are natural errors. Random errors in experimental measurements are caused by unknown and unpredictable changes in the experiment. Systematic errors are due to imprecision or problems with instruments.
Answer:
The volume of the submerged part of her body is 
Explanation:
Let's define the buoyant force acting on a submerged object.
In a submerged object acts a buoyant force which can be calculated as :
ρ.V.g
Where ''B'' is the buoyant force
Where ''ρ'' is the density of the fluid
Where ''V'' is the submerged volume of the object
Where ''g'' is the acceleration due to gravity
Because the girl is floating we can state that the weight of the girl is equal to the buoyant force.
We can write :
(I)
Where ''W'' is weight
⇒ If we consider ρ =
(water density) and
and replacing this values in the equation (I) ⇒


ρ.V.g = 610N
(II)
The force unit ''N'' (Newton) is defined as

Using this in the equation (II) :



We find that the volume of the submerged part of her body is 
Y, bc the height of the bounce back is higher than x