Answer:
8 + 2 n (second expression listed)
Explanation:
Since we don't know the number, we represent it with a letter (n).
Twice a number (two times that number) will therefore be: 2 n.
and the addition (sum) of 8 to such will lead to 8 + 2 n
The sum of 8 and twice a number is : 8 + 2 n
Explanation:
Energy transfer is the movement of energy from one location to another. For example, when electricity moves from a wall plug, through a charger, to a battery.
Energy transformation is when energy changes from one form to another – like in a hydroelectric dam that transforms the kinetic energy of water into electrical energy.
Answer:
The acceleration is 2.448 meters per square second and is vertically upward.
Explanation:
The Free Body Diagram of the plastic ball in the liquid is presented in the image attached below. By Second Newton's Law, we know that forces acting on the plastic ball is:
(1)
Where:
- Buoyant force, measured in newtons.
- Mass of the plastic ball, measured in kilograms.
- Gravitational acceleration, measured in meters per square second.
- Net acceleration, measured in meters per square second.
If we know that 
, 
and 
, then the net acceleration of the plastic ball is:
The acceleration is 2.448 meters per square second and is vertically upward.
Answer:
Displacement = 30 miles due east.
Explanation:
Let the distance due west be A
Let the distance due east be B
Given the following data;
A = 50 miles
B = 80 miles
To find the displacement;
Displacement can be defined as the change in the position of a body or an object. It is a vector quantity because it has both magnitude and direction.
Thus, the displacement would be calculated by subtracting distance A from distance B because the rider rode in opposite directions.
Displacement = B - A
Displacement = 80 - 50
Displacement = 30 miles due east.
Answer:
the maximum frequency observed is 2.0044 10⁶ Hz
Explanation:
This is a Doppler effect exercise. Where the emitter is still and the receiver is mobile, therefore the expression that describes the process is
f ’= 
the + sign is used when the observer approaches the source
typical speeds of a baby's heart stop are around 200 m / min
let's reduce to SI units
v₀ = 200 m / min (1 min / 60 s) = 3.33 m / s
let's calculate
f ’= 2 10⁶ (
)
f ’= 2.0044 10⁶ Hz
f ’= 1,9956 10⁶ Hz
therefore the maximum frequency observed is 2.0044 10⁶ Hz
