1. An electron moves with velocity of 6.0x10⁶ m/s perpendicular to a magnetic field facing out of the page. The circular path of the electron has radius of 3 mm. (a) draw sketch of the magnetic field and path of electron. Determine (b) the magnitude of the B field, (c) acceleration of the electron (m_e= 9.11x10^-31 kg, e=60x10^-19 C).
2. When a magnetic flux through 5 loops of wire increases by 30.0 T.m², an average current of 40.0 A is induced in the wire. Assuming that the wire has a resistance of 2.5 ohms, (a) over what period of time did the flux increases? (b) If the area of the loop is 0.08 m², perpendicular to the magnetic field and the flux change is only due to change of magnetic field, how much the field changes during this time period ?
3. A metal airplane with a wingspan of 30.0 m flies horizontally along a north-south route in the northern hemisphere at a constant speed of 320.0 km/h in a region where the vertical component of the Earth’s magnetic field is 5.0 x10^-5 T. (a) What is the magnitude of the induced emf between the tips of the wings. (b) If the easternmost wing tip is negatively charged, is the plane flying due north or due south, explain?

1. ​A negative pion ( ) is a particle that​ ​has a mass equal to 2.49 x 10​-28​ kg. What is the rest π− energy of the pion in joules and in megaelectron-volts (MeV)?

2. ​A negative pion is observed to be moving to the right at 0.950​c ​ .​ ​ What is the negative pion’s total energy (in MeV) ​and ​ momentum at this speed?

3. ​The negative pion decays (splits) into two particles, a muon ( ) and a neutrino ( ). The μ υ muon has a rest energy of 106 MeV, and the neutrino is (virtually) massless. After the decay, the total energy of the neutrino is observed to be 187 MeV. How much total energy must the ​muon ​ have?

4. ​ At what speed is the muon observed to be travelling?

5.  On Earth in 2017, the amount of electrical energy used was 8.03 x 10​16​ J. How much mass would need to be converted directly to energy to release this much energy?

6.  Imagine this conversion of mass to energy all came from nuclear fission reactions of the element uranium. Assume the reaction is 35% efficient: that means that the mass you calculated above to produce the electrical energy is only 35% of the total mass that was converted to energy. The other 65% was “waste” energy. How much total mass was converted to all kinds of energy?

7. The amount of mass actually converted to energy is just a small fraction of the original uranium’s mass: just 0.0000885 of the original mass (0.00885%). Given all these assumptions, how much total mass of uranium must be available to create all the electrical energy used in the world, in one year? (The total reserve of uranium-235 currently available is about 37,000 tonnes, or 3.7 x 10​7​ kg.).

. If a string fixed at both ends resonates in its fundamental mode with a frequency of 150 Hz, at which of the following frequencies will it not resonate?

2. (a). Prove that the sum of the two projection operators is not a projection operator, unless the multiplication of the two projection operators produces a zero value.

(b). Prove that the result of the multiplication of two projection operators is not a projection operator, unless the two projection operators are hermitian.

Tell me about the formula and principle of obtaining the focal length and size of the Zoom lens with one convex lens and two concave lenses.

Using complete sentences and the concepts discussed in Chapter 15 and 16 (including the type of heat transfer, frequency, wavelength, and energy) describe the greenhouse effect, and how it determines the temperature of Earth (or enclosed objects)

Describe a way to produce energy that causes no environment harm

1.

You throw a 50kg ball upwards at 25m/s. The ball strikes the beginning of the spring when it's 8 meters in the air, then it begins to compress the spring. How far did the spring compress? The spring constant is 300 Newton/meter.

Also, if the spring was not there, how far would have it gone up (set the final velocity to zero)?

2.

You see a teeter-todder again. It's horizontal (balanced). A 100kg person sits 4 meters to the right, and a 30kg person sits 8 meters to the left (of the pivot). On what side, and where, must a 69kg person sit for it to balance? And what force must the ground push up on the tetter-todder, in order for it to not fall down (find the ground's normal force)?

Starting from rest, a truck travels in a straight line for 7.0 s with a uniform acceleration of +1.6 m/s2. The driver then applies the brakes for 3.0 s, causing a uniform acceleration of −2.0 m/s2 over that time. (a) What is the truck's speed at the end of the braking period? (b) What is the total distance traveled by the truck (from the point where it started at rest to the end of the braking period)

Relative humidity isn't everything. Why is it that outdoor air of 80 Fo at 55% humidity will feel more “muggy” than a 50 Fo cave at 75% humidity? What other parameter is a better measure of the actual amount of moisture in the air, and how do we define it? Then give two examples of when keeping close track of moisture in the air is important.

i want to ask about underwater applications of lifi.as we know that that that light caannot travel much in water it is used for short range communications then what should be these short range applications.another question is that why visible light cannot cross the walls but radio waves do?

You have a glass ball with a radius of 2.00 mm and a density of 2500 kg/m3. You hold the ball so it is fully submerged, just below the surface, in a tall cylinder full of glycerin, and then release the ball from rest. Take the viscosity of glycerin to be 1.5 Pa s and the density of glycerin to be 1250 kg/m3. Use g = 10 N/kg = 10 m/s2. Also, note that the drag force on a ball moving through a fluid is:

Fdrag = 6πηrv .

(a) Note that initially the ball is at rest. Sketch (to scale) the free-body diagram of the ball just after it is released, while its velocity is negligible.

(b) Calculate the magnitude of the ball’s initial acceleration.

(c) Eventually, the ball reaches a terminal (constant) velocity. Sketch (to scale) the free-body diagram of the ball when it is moving at its terminal velocity.

(d) Calculate the magnitude of the terminal velocity.

(e) What is the magnitude of the ball’s acceleration, when the ball reaches terminal velocity?

(f) Let’s say that the force of gravity acting on the ball is 4F, directed down. We can then express all the forces in terms of F. (For instance, you might label a force on a free-body diagram as “Fdrag = 3F”.) Sketch three free-body diagrams, and express all forces in terms of F. Hint: do the middle one last.

Initial FBD FBD for when v = half FBD for when (when released from rest) the terminal velocity v = terminal velocity

(g) How does the net force in the left-most free-body diagram compare to that in the middle free-body diagram? Combine that information with your result from problem 1, regarding the initial acceleration, to find the magnitude of the acceleration when the ball’s speed is half the terminal speed.

(h) Take down to be positive for all your graphs. (i) Sketch a grapch of the ball’s acceleration as a function of time; (ii) sketch a graph of the ball’s velocity as a function of time; (iii) sketch a graph of the ball’s position as a function of time. If you can be quantitative with your axis labels, then do so.

A 50-g cube of ice, initially at 0.0°C, is dropped into 200 g of water in an 80-g aluminum container, both
initially at 30°C. What is the final equilibrium temperature? (Specific heat for aluminum is 900 J/kg×°C,
the specific heat of water is 4 186 J/kg×°C, and Lf = 3.33 ´ 105 J/kg.)