Questions
What is angular momentum?

What is angular momentum?

In: Physics

In detail, explain what role magnetism play in the 'Charge to Mass ratio of an electron'...

In detail, explain what role magnetism play in the 'Charge to Mass ratio of an electron' experiment performed by J.J. Thomson?

How can magnetism alter the expected results?

Why is it important for the electron beam to be perpendicular to all non-negligible magnetic fields?

In: Physics

A uniform 45 kg beam that is 4.35 m in length sticks out from a vertical...

A uniform 45 kg beam that is 4.35 m in length sticks out from a vertical wall. A lightweight cable connects the end of the beam to the wall, making an angle of 60.0° between the beam and the cable. A 65 kg worker stands on the beam a distance of 1.75 m from the wall. What is the tension in the cable?

In: Physics

I know that the type 1A Supernova stars are ideal to measure distances and to prove...

I know that the type 1A Supernova stars are ideal to measure distances and to prove that the universe is accelerating.

They are standard candles type of stars. Their luminosity will decline after explosion.  They shine as brightly as an entire galaxy for a few weeks or months then gradually fade away.

By analyse the velocity obtained by the redshift and the distance the star is from us we can assume that the universe is accelerating.  But if I know the velocity and the distance, still how can I conclude the universe is accelerating? Plus, what this has to do with dark matter? And is the Universe gonna stop expending eventually?

I hope someone can help me with a clear explanation.

In: Physics

A thin film of oil (n = 1.28) is located on smooth, wet pavement. When viewed...

A thin film of oil (n = 1.28) is located on smooth, wet pavement. When viewed from a direction perpendicular to the pavement, the film reflects most strongly red light at 640 nm and reflects no light at 427 nm. What is the minimum thickness of the oil film?
nm

In: Physics

In warehouses, boxes get lifted up and down a lot, which is usually done by a...

In warehouses, boxes get lifted up and down a lot, which is usually done by a forklift. A forklift has a maximum load it can handle so you need to know the force acting on the fork. As an example assume that you want to lift two heavy boxes with a forklift. The lower box A has a mass of 150 kg and the upper box B has a mass of 100 kg. Use g = 9.8 ?/?2

a) What is the magnitude of the force (in Newtons) that the forklift exerts on the lower box A while the boxes are moving up at constant speed?

b) What is the magnitude of the force (in Newtons) that the upper box B exerts on the lower box A while the boxes are moving up at constant speed?

c) The forklift has just picked up the boxes off the ground. What is the magnitude of the force that the forklift exerts on box A while the boxes move up and speed up with an upward acceleration of ?=0.5?/?2 ?

d) Assume that the forklift has picked up the boxes from a high shelf and is lowering them to the ground. What is the magnitude of the force the upper box exerts on the lower box while the boxes are slowing down at a rate of ?=0.5?/?2

In: Physics

1) Suppose after charging a 5.8

1) Suppose after charging a 5.8

In: Physics

A fan is designed to last for a certain time before it will have to be...

A fan is designed to last for a certain time before it will have to be replaced (planned obsolescence). The fan only has one speed (at a maximum of 650 rpm), and it reaches the speed in 2.0 s (starting from rest). It takes the fan 7.0 s for the blade to stop once it is turned off. The manufacturer specifies that the fan will operate up to 1 billion rotations. Andre lives in a hot climate, works outside of the home from approximately 8:00 am to 5:00 pm, Monday through Friday, does not own an air conditioner, and can't sleep with the fan running. Estimate how many hot days ?hot Andre will be able to use the fan, rounded to the nearest day.

In: Physics

Discuss evidence of craters on Earth. you may discuss any other craters that we know of...

Discuss evidence of craters on Earth. you may discuss any other craters that we know of on Earth. You could also discuss the issue of craters on Earth in general.

In: Physics

Solve the following ordinary differential equations by separating variables and integration. 1. y'sinx=ylny, the boundary condition...

Solve the following ordinary differential equations by separating variables and integration.
1. y'sinx=ylny, the boundary condition (b.c.) is that the function passes through (y=e,x=pi/3)
2. y'+2xy2=0, b.c. (y=1;x=2)
3. y'-xy=x, b.c. (y=1;x=0)

In: Physics

atoms with angular momentum s=1 is sent through a Stern-Gerlach apparatus oriented in the z (represented...

atoms with angular momentum s=1 is sent through a Stern-Gerlach apparatus oriented in the z (represented as SGz) direction and only the mz = 0 atoms are allowed to go through other sides.

1. Calculate the output at SGx

2. suppose one state (I 1 -1 > )x emerges . What happens if these beams are sent through SGz

In: Physics

Why do the laws of physics exist? Why does nature behave the way it does? Why...

Why do the laws of physics exist?
Why does nature behave the way it does?
Why is there a connection between math and nature?
Science can tell us a lot about how nature works, but it can't (and doesn't try to) answer the question, "Why?"
What ideas do you have on the subject? Your answer may involve your culture, religion or lack of religion, philosophy, or other ideas.

In: Physics

A negative charge of –40nC exerts an attractive force of 12N on a second charge that...

A negative charge of –40nC exerts an attractive force of 12N on a second charge that is 0.050m away. What is the second charge?

In: Physics

What is the difference between induction and charging by conduction?

What is the difference between induction and charging by conduction?

In: Physics

A charge of uniform linear density 2.20 nC/m is distributed along a long, thin, nonconducting rod....

A charge of uniform linear density 2.20 nC/m is distributed along a long, thin, nonconducting rod. The rod is coaxial with a long conducting cylindrical shell (inner radius = 4.00 cm, outer radius = 9.00 cm). The net charge on the shell is zero. (a) What is the magnitude of the electric field at distance r = 13.0 cm from the axis of the shell? What is the surface charge density on the (b) inner and (c) outer surface of the shell?

In: Physics