A disk (radius 95.8 cm] rotates about a fixed axis through its center of mass and perpendicular to the disk. At t = 0 the disk is rotating at frequency 6.47 Hz, and it accelerates uniformly to frequency 73.8 Hz after spinning through 38.4 revolutions. Find the angular acceleration of the disk, in rad/s².

The wheel of a cart has radius 53.9 cm. How many revolutions will it make if the cart goes 2.79 km?

An electric fan is turned off, and it slows down from 639 revolutions/s to 30 revolutions/s in 1.94 seconds. How many times did the fan blades spin in this time?

A book weighing 5 N rests on top of a table.

Part A

A downward force of magnitude 5 N is exerted on the book by the force of

Part B

An upward force of magnitude _____ is exerted on the _____ by the table.

6N/table

5N/table

5N/book

6N/book

Part C

Do the downward force in Part A and the upward force in Part B constitute a 3rd law pair?

Part D

The reaction to the force in Part A is a force of magnitude _____, exerted on the _____ by the _____. Its direction is _____ .

5N/ earth/ book/ upward

5N/ book/ table/ upward

5N book/ earth/ upward

5N/ earth/ book/ downward

Part E

The reaction to the force in Part B is a force of magnitude _____, exerted on the _____ by the _____. Its direction is _____.

5N T/B/U

5N T/E/U

5N B/T/U

5N T/B/D

5N E/B/D

Part F

Which of Newton's laws could we have used to predict that the forces in Parts A and B are equal and opposite?

Check all that apply

.

Part G

Which of Newton's laws could we have used to predict that the forces in Parts B and E are equal and opposite?

Check all that apply.

Everyday lighting takes a lot of energy and comparison with sports can be illustrative.

a) How much energy is consumed by a 60 W lightbulb if it’s turned on for only 1 min?

b) If a kicked soccer ball had this much kinetic energy how fast would it be moving in miles per hour?

c) How long would it take a ball moving at this speed to cross the 100m soccer field?

d) Realistically a soccer ball might be kicked at 20m/s. If the kinetic energy of such a ball were used to light the 60 W bulb,how long would the bulb be on?

Q3- lens A to be a convex lens with a focal length of 20 cm, lens B is concave lens with focal length of 15 cm a- Calculate and compare the optical powers for lenses A, and B b- Find the combined optical power if the two lenses were cascaded behind each other

Q4- Use ray tracing or Lens equation to find the image of an object 1 cm high located at 2 cm away from a convex lens that have a focal length of 4 cm. find the image type( real/virtual ) location, orientation, and magnification.

A single point charge +Q is at the center of a thin spherical sheet that carries a net charge of – 3Q and has a radius of a. Your goal is to calculate the electric field at a distance r away from the center of the spherical sheet.
(A) Draw the situation below. Represent a in your diagram. You should NOT have r in your diagram.










(B) Use Gauss’s law to calculate the electric field when r < a (i.e., inside the spherical sheet). a. What surface should you use in order to do this? Draw this surface on your diagram above. b. Use Gauss’s law to calculate the electric field inside the spherical shell.









(C) Use Gauss’s law to calculate the electric field when r > a (i.e., outside the spherical shell) a. What surface should you use in order to do this. Draw this surface on the diagram above. b. Use Gauss’s law to calculate the electric field outside the spherical shell.








(D) On the coordinate axes below, plot the electric field magnitude as a function of r. Hint: The electric field is a piece-wise defined function with different expressions in different regions

A 3.3 kg object is pulled by 4 ropes. One rope is used to pull the object 15° North of East with a force of 25 N. A second rope pulls it due south with a force of 15 N. A third pulls the object 22° west of north with a 36 N magnitude. If the object is moving due west with a constant acceleration (a=1.0 m/s^2 ), describe the force (magnitude and direction) applied by the 4th rope.

A group of particles is traveling in a magnetic field of unknown magnitude and direction. You observe that a proton moving at 1.70 km/skm/s in the +x+x-direction experiences a force of 2.06×10⁻¹⁶ NN in the +y+y-direction, and an electron moving at 4.70 km/skm/s in the −z−z-direction experiences a force of 8.10×10⁻¹⁶ NN in the +y+y-direction.

What is the magnitude of the magnetic field?

What is the direction of the magnetic field? (in the xzxz-plane)

What is the magnitude of the magnetic force on an electron moving in the −y−y-direction at 3.60 km/skm/s ?

What is the direction of this the magnetic force? (in the xzxz-plane)

A magnifying glass uses a converging lens with a focal length of 15.5 cm. It produces a virtual and upright image that is 2.9 times larger than the object.

A) How far is the object from the lens?

B) What is the image distance?

A car traveling 37.0 m/s overtakes another car going only 21.0 m/s. When the faster car is still behind the slower one, it sounds a horn of frequency 1400.0Hz. What is the frequency heard by the driver of the slower car?

You have a rocket with a mass of 2.5kg, that provides a total forward force of F=49N. a.) At what angle must you launch it so that it flies perfectly horizontally. b.) Now you set it up to launch vertically. From rest it takes off but it only has enough fuel to burn for 10 seconds. How high does it get? c.) If it launched at 45 degrees, the fuel burnt for 10 seconds, then it fell to the ground, how far away from its original position would it land?

5. Give an example of a real-world system that looks nothing like a mass on a spring but still behaves like a harmonic oscillator. The weirder the better!

can you please explain the example as well

A converging lens with a focal length of 11.8 cm forms a virtual image 8.35 mm tall, 18.0 cm to the right of the lens.

1.) Determine the position of the object. (answer in cm)

2.) Determine the size of the object. (answer in cm)

3.) Is the image erect or inverted? Select one.

4.) Are the object and image on the same side or opposite sides of the lens? Select one.

The table that follows lists four pairs of initial and final angles of a wheel on a moving car. The elapsed time for each pair of angles is 1.5 s. For each of the four pairs, determine the average angular velocity (magnitude and direction as given by the algebraic sign of your answer).

A 0.294-m-thick sheet of ice covers a lake. The air temperature at the ice surface is -17.7 °C. In 3.00 minutes, the ice thickens by a small amount. Assume that no heat flows from the ground below into the water and that the added ice is very thin compared to 0.294 m. Calculate the number of millimeters by which the ice thickens. Do not enter unit.