Answer:
Explanation:
Given
Distance to grandmother's house=100 mi
it is given that during return trip Julie spend equal time driving with speed 30 mph and 70 mph
Let Julie travel x mi with 30 mph and 100-x with 70 mph

x=30 mi
Therefore
Julie's Average speed on the way to Grandmother's house
=42 mph
On return trip

Answer:
Resultant force, R = 10 N
Explanation:
It is given that,
Force acting along +x direction, 
Force acting along +y direction, 
Both the forces are acting on a point object located at the origin. Let the resultant force of the object is given by R. So,

Here 


R = 10 N
So, the resultant force on the object is 10 N. Hence, this is the required solution.
The atom is the most basic unit of matter
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 