(a) Explain briefly what is meant by atmospheric pressure, and why it decreases with altitude.

(b) Explain the role of the Earth’s magnetosphere in protecting the atmosphere from solar wind, and in creating the auroras.

(c) Why is the sky blue? Would you expect to see blue skies on other planets?

Write an example "background" information for exponential decay using beer froth experiment:

Do the rays reflected from the plane mirror obey the Law of Reflection? Explain.

Humans have little or no sensitivity to polarized light, and no sensitivity at all to ultraviolet light while many invertebrates such as insects do. In what way do you think this would be useful to an organism?

In words, but making use of equations where appropriate, explain how the Principal of Conservation of Linear Momentum is a demonstration of Newton’s third law of motion. In particular, consider a simple collision between two objects. The collision may be either elastic or inelastic. It may be head-on or oblique. State how the changes in motion as a result of this collision relate to Newton’s Third Law. Finally expand your reasoning to cover a many particle system.

In words, but making use of equations where appropriate, explain how the Principal of Conservation of Linear Momentum is a demonstration of Newton’s third law of motion. In particular, consider a simple collision between two objects. The collision may be either elastic or inelastic. It may be head-on or oblique. State how the changes in motion as a result of this collision relate to Newton’s Third Law. Finally expand your reasoning to cover a many particle system.

Please help me with this question, thank you

Suppose you have a system of two masses strung over a pulley. Mass 1 (6.2 kg) hangs on the right side of the pulley suspended over the ground at height 0.7 m. Mass 2 (2.3 kg) hangs over the left side of the pulley and rests on the ground. The pulley is a uniform disk of mass m and radius 12.5 cm. When the system is released, Mass 1 moves down and Mass 2 moves up, such that Mass 1 strikes the ground with speed 0.7 m/s. This is called an Atwood Machine. Calculate the mass of the pulley in kg.

A -6µC charge and a 3µC charge are placed 1.5 meters apart, with the -6µC charge on the left side and the 3µC charge on the right side. Use figure with arrow lines, as well as mathematical calculation to determine the following:Will you be able to place a -2µC charge outside of the -6µC charge so that the net force from coming from the 3µC and -6µC charges add up to be zero? If not, why? If so, where is the spot?

Will you be able to place a -2µC charge outside of the 3µC charge so that the net force from coming from the 3µC and -6µC charges add up to be zero? If not, why? If so, where is the spot?

Will you be able to place a -2µC charge between the -6µC and 3µC charges so that the net force from these two charges add up to be zero? If not, why? If so, where is the spot?

A double-slit is illuminated with monochromatic light in the air and it turns out that the first order minima occur at angles ∓35.09 ° relative to the reference line from the double slit to central max. If the double slit is lowered into a transparent liquid and illuminated with the same light, the first order minima occur at the angles ± 19.36 °. Decide the refractive index of the liquid?

Explain how photodiode array(PDA)-based single beam UV-Vis spectrophotometer works(illustrate your explanation by drawing a schematic diagram)

What is the main advantage of the PDA-based (reverse optics) single beam instruments compared to the conventional single beam ones?

There are two speakers at the front of the room. Each is outputting a 250Hz pure tone. For each of the following situations, will you hear constructive interference (a loud noise) or destructive interference (soft or no noise). ? represents the wavelength of the 250Hz tone.

You are 3? away from speaker A; 2? away from speaker B and at the speakers the waves are exactly in phase.

You are 3? away from speaker A; 2.5? away from speaker B and at the speakers the waves are exactly in phase.

You are 3? away from speaker A; 4? away from speaker B and at the speakers the waves are exactly out of phase.

You are 3? away from speaker A; 2.5? away from speaker B and at the speakers the waves are exactly out of phase.

M4. Discussion: Frictionless World

Topic

In this module, we examined the concept of friction and how it affects everything we do. Air resistance is an important type of friction that you don’t want to forget about as you prepare your post. Consider what the world would be like without friction. For example, in a world without friction, the pitcher in a baseball game can still pitch the ball because he can push off the pitching rubber. The pitching rubber is the rubber slab atop the pitching mound that a pitcher uses to push off to gain velocity. But what happens when the batter swings or when the ball hits the catcher’s mitt?

Now, think of one of your favorite sports or another activity you enjoy. How would the action of that activity be different in a world without friction? In your initial post to the discussion, describe your activity and then respond to the following:

1. Describe at least three ways your activity would change if friction were taken out of the scenario.
2. Does friction make it easier or harder to participate in your activity?
3. What are some advantages and disadvantages that you might encounter if there wasn’t friction in our world?

Finally, be sure to respond to at least two of your peers’ discussion posts.

A thin film of MGF₂ has a refractive index of n = 1.38 and it is deposited on glass as an anti-reflective layer of light with a wavelength of 580nm which falls in the normal direction towards the film. What wavelength is minimally reflected when the light falls at 45 ° towards the film?

3) A 2 kg block is sliding at an initial speed of 10 m/s across a surface, encountering a constant friction force of 7 N. How much work is done on the block after it slides 22 cm?

Answer:  

Hint: Does the block gain or lose energy during this process? What sign does this imply for the work done on it?

4) How fast is the block moving after sliding 22 cm?

Answer:  

Hint: You can treat the block like a simple particle. What kind of energy does it have and how is this affected by the work done on it?

5) What's the total distance the block travels before coming to rest?

Correct, computer gets: 14.29 m

6) What is the average power of friction on the block over the time it takes the block to come to rest?

Answer:  


7) What was the instantaneous power of friction on the block after it slid the first 22 cm?

Answer