There are hundreds of moons in our solar system, and they come in many shapes, sizes, and types. Does Kepler’s law of planetary motion apply to moons? Explain.
Why were Kepler’s Laws so important? What paradigm shift took place due to his laws?
If the same force acts on the Moon from the Earth -and- on the Earth from the Moon, why does the Moon orbit the Earth and not vice versa?
How is weight different from mass. If you really just want to weigh less (assuming infinite budget and resources!), what should you do?
Newton’s addition to Kepler’s third law made it possible to know the mass of a star by looking at how planets orbit around it. How would you expect planets
move if they orbited a very massive star compared to a very non-massive star (assume the same orbital distance)?
Category: Physics
Physics
Question 1 (6 marks)
a) Newton’s universal law of gravitation describes the force of gravity acting on two masses. The
correct equation is,
Fg = G
m1m2
r
2
.
Using dimensional analysis, determine the dimensions and SI units for the gravitational constant
G. Here, Fg is a force, m1 and m2 are masses and r is a distance. (2 marks)
b) Someone then tells you that the equation for gravitational potential energy U (measured in
Joules) is,
U = −G
m1m2
r
3
.
Using dimensional analysis, determine if they are correct. (1 mark)
c) An experiment determined that the time for a star to orbit a black hole T in a circular orbit
depends on the distance from the black hole to the star r, the gravitational constant G and the
mass of the black hole m. That is,
T = CrαG
βmγ
where C is a dimensionless constant. Using only dimensional analysis, determine what the
exponents α, β and γ must be for this equation to be correct. (3 marks)
Question 2 (7 marks)
Answer the following given the two vectors written in standard position.
A⃗ = 4m/s @ 220o B⃗ = 7m/s @ 300o
a) Draw a diagram for A⃗ and write A⃗ in terms of ˆi and ˆj (answer to 2 decimal places). (2 marks)
b) Draw a diagram for B⃗ and write B⃗ in terms of ˆi and ˆj (answer to 2 decimal places). (2 marks)
c) Determine the angle θ between A⃗ and B⃗ using the dot product. Then draw a diagram and use
geometry to verify your answer. (3 marks)
Question 3 (8 marks)
Answer the following given the two vectors (measured in meters).
A⃗ = −4ˆi + 10ˆj + ˆk B⃗ = 5ˆi + 5ˆk
a) Using only the dot product (no cross products) determine a unit vector Cˆ that is perpendicular
to both A⃗ and B⃗ . I recommend checking that your answer is indeed perpendicular to both A⃗ and
B⃗ by taking a dot product with each. (6 marks)
b) Determine the angle ϕ (Greek letter for F, pronounced ’f-eye’) between Cˆ and the z-axis (answer
to 2 decimal places). (2 marks)
Physics
Question 1 (6 marks)
a) Newton’s universal law of gravitation describes the force of gravity acting on two masses. The
correct equation is,
Fg = G
m1m2
r
2
.
Using dimensional analysis, determine the dimensions and SI units for the gravitational constant
G. Here, Fg is a force, m1 and m2 are masses and r is a distance. (2 marks)
b) Someone then tells you that the equation for gravitational potential energy U (measured in
Joules) is,
U = −G
m1m2
r
3
.
Using dimensional analysis, determine if they are correct. (1 mark)
c) An experiment determined that the time for a star to orbit a black hole T in a circular orbit
depends on the distance from the black hole to the star r, the gravitational constant G and the
mass of the black hole m. That is,
T = CrαG
βmγ
where C is a dimensionless constant. Using only dimensional analysis, determine what the
exponents α, β and γ must be for this equation to be correct. (3 marks)
Question 2 (7 marks)
Answer the following given the two vectors written in standard position.
A⃗ = 4m/s @ 220o B⃗ = 7m/s @ 300o
a) Draw a diagram for A⃗ and write A⃗ in terms of ˆi and ˆj (answer to 2 decimal places). (2 marks)
b) Draw a diagram for B⃗ and write B⃗ in terms of ˆi and ˆj (answer to 2 decimal places). (2 marks)
c) Determine the angle θ between A⃗ and B⃗ using the dot product. Then draw a diagram and use
geometry to verify your answer. (3 marks)
Question 3 (8 marks)
Answer the following given the two vectors (measured in meters).
A⃗ = −4ˆi + 10ˆj + ˆk B⃗ = 5ˆi + 5ˆk
a) Using only the dot product (no cross products) determine a unit vector Cˆ that is perpendicular
to both A⃗ and B⃗ . I recommend checking that your answer is indeed perpendicular to both A⃗ and
B⃗ by taking a dot product with each. (6 marks)
b) Determine the angle ϕ (Greek letter for F, pronounced ’f-eye’) between Cˆ and the z-axis (answer
to 2 decimal places). (2 marks)
si(li）detector
literature review of si(li) detector, we can devide the paper into: dead layer
Manufacturing time
Rate of count of particles
Uniform distribution of Li ions in Si detectors
Size of si(li) detector.
Or by other way. thank you very much.
AC and DC Generators
How do AC and DC generator output and uses differ?
How do AC and DC generators relate to AC and DC motors?
AC and DC Generators
How do AC and DC generator output and uses differ?
How do AC and DC generators relate to AC and DC motors?
AC and DC Generators
How do AC and DC generator output and uses differ?
How do AC and DC generators relate to AC and DC motors?
How the series and parallel systems function together
Discuss how the series and parallel systems function together as a series-parallel circuit in your analogy.
while the organs are the parallel circuits the blood paths are the series circuits. The blood starts at the heart and gets sent throughout the body and back to the heart. The blood also goes to the organs in order to allow them to go through the process that they need to do. As the blood also goes through the organ it continues on until the veins turn around and bring the blood back to the heart.
How electricity can travel through the body using a series-parallel electrical model.
Explain how electricity can travel through the body using a series-parallel electrical model. How does this relate to touch, step, and step-touch potential?
touch something that is electrified and the current flow from your hand to the middle of your body which is series and down through your legs which is a parallel, this is touch potential. Step on an electrified object and do not touch anything else, the current would flow from one foot and down the other foot, this is step potential.
The loading effect of a voltmeter on a circuit.
Discuss the loading effect of a voltmeter on a circuit. How does the voltmeter’s internal resistance affect the loading effect?
The loading effect on a voltmeter does not really effect lower resistance circuits and only effect higher resistance circuits. there is no difference on low resistance circuits but with higher resistance circuits it lowers the voltage for that part of the circuit showing a lower voltage.