Answer: 5.5m/s
Explanation:
vf=vi+at
vf= 4.0m/s + (0.50m/s^2)(3.0s)
Answer:
0.20
Explanation:
The box is moving at constant velocity, which means that its acceleration is zero; so, the net force acting on the box is zero as well.
There are two forces acting in the horizontal direction:
- The pushing force: F = 99 N, forward
- The frictional force: 
, backward, with
coefficient of kinetic friction
m = 50 kg mass of the box
g = 9.8 m/s^2 gravitational acceleration
The net force must be zero, so we have
which we can solve to find the coefficient of kinetic friction:
Answer:
0.306mm
Explanation:
The radius of the conductor is 3mm, or 0.003m
The area of the conductor is:
A = π*r^2 = π*(.003)^2 = 2.8*10^-5 m^2
The current density is:
J = 130/2.8*10^-5 = 4.64*10^6 A/m
According to the listed reference:
Vd = J/(n*e) = 4.64*10^6 / ( 8.46*10^28 * 1.6*10^-19 ) = 0.34*10^-6 m/s = 0.34mm/s
The distance traveled is:
x = v*t = 0.34 * .90 = 0.306 mm
Answering the question, three examples of ways that physicists model the physical world include:
- Diagrams
- Equations
- Computer simulations
Computer simulations refer to the reproduction of behavior of a system with the use of a computer to simulate the results of a mathematical model that is linked with the system.
<h2>Further Explanation</h2>
Computer simulations are a tool that is very useful for mathematical modeling in various natural systems in physics.
Physicists write the rule of our universe using equations. Equations are an aspect of one of the models used by physicists to explain a particular situation.
Physicists use a diagram to convey information. It is a symbolic representation of information with the use of visualization techniques. Diagram provides other means for people to better understand information and process its importance.
Physics predictions about the physical world mainly depend on numerical stimulation, mathematics and empirical observations and Physicists models the physical world based on invariances and laws which are built on mathematical models.
The purpose of physics is to explain or describe everything around us. It described virtually everything around us accurately by deploring the law of physics.
However, physics is considered a natural science because it is based on mathematical analysis which is geared towards findings qualitative physical law for the physical world.
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KEYWORDS:
- physicists
- physics
- models
- physical world
- computer simulations
- diagrams
- equations
Answer:
2. + 2.1
Explanation:
Formula for resistance is as follows
R_t = R₀ ( 1 + α t )
R_t is resistance at changed temperature , Ro is resistance at initial temperature , α is temperature coefficient of resistivity . t is temperature change .
For iron , R₀ = 10 , α = 5 x 10⁻³ , t = - 100 degree
R_t = 10( 1 + 5 x 10⁻³ x - 100 )
= 10( 1 - 5 x 10⁻³ x 100 )
10 x ( 1 - .5 )
10 x .5
For carbon
, R₀ = 10 , α = - 0.5 x 10⁻³ , t = - 100 degree
R_t = 10( 1 - 0. 5 x 10⁻³ x - 100 )
= 10( 1 + .5 x 10⁻³ x 100 )
10 x ( 1 + .05 )
10 x 1.05
Required ratio
= 10 x 1.05 / 10 x .5
= 105 / 50
= 21 / 10
= 2.1
