Answer:
A. Acceleration always involves changing speed.
Explanation:
Acceleration is defined as the rate of change of velocity.
Velocity is a vector quantity and is defined as speed in a given direction. Therefore, when any or both of the components of velocity is changing with time, a body is said to be accelerating i.e. acceleration involves a change of speed or change in direction, or a change in both speed and direction.
Considering the statements:
A. Acceleration always involves changing speed is false because acceleration can occur when speed is constant but direction is changing.
B. Changing direction always involves acceleration is true because, a change in direction results in a change in velocity.
C Changing speed always involves acceleration is true because, changing speed results in a change in velocity.
D. Circular motion always involves acceleration is true because in circular motion the direction is always changing, and this results in a change in velocity
Answer;
-A model
Explanation;
-A mathematical model is an abstract model that uses mathematical language to describe the behavior of a system. A Mathematical Model tries to copy how a real world thing works using equations.
-Usually a mathematical model describes a system by a set of variables and a set of equations that establish relationships between the variables. Variables may be of many types; real or integer numbers, for example.
-The Area A of a circle with radius r is given by the formula A = πr2. In this formula π ≈ 3.1416... is a number which is a constant, and A and r are variables or unknowns. A is called the subject of the formula.
Given:
distance from the projector lens to the image, di
projector lens focal length, f
distance from the transparency to the projector lens, do
thin lens equation: 1/f = 1/di + 1/do
do = 4 inches
di = 8 feet
convert feet to inches, for uniformity.
1 foot = 12 inches
8 feet * 12 inches/ft = 96 inches
1/f = 1/96 inches + 1/4 inches
Adding fractions, denominator must be the same.
1/f = (1/96 * 1/1) + (1/4 * 24/24)
1/f = 1/96 + 24/96
1/f = 25/96
to find the value of f, do cross multiplication
1*96 = f * 25
96 = 25f
96/25 = f
3.84 = f
The focal length of the project lens is 3.84 inches
B nitrogen stays in order so it can't change movement
