Discuss Einstein and Planck's collaborative work on the photoelectric effect and their differing views about whether science research is removed from social and political forces.

The rotor in a certain electric motor is a flat, rectangular coil with 89 turns of wire and dimensions 2.57 cm by 4.20 cm. The rotor rotates in a uniform magnetic field of 0.800 T. When the plane of the rotor is perpendicular to the direction of the magnetic field, the rotor carries a current of 10.6 mA. In this orientation, the magnetic moment of the rotor is directed opposite the magnetic field. The rotor then turns through one-half revolution. This process is repeated to cause the rotor to turn steadily at an angular speed of 3.72 103 rev/min.

(a) Find the maximum torque acting on the rotor.
0.000815N

A lens has a power of -1.72 D. You look through it a 1.00-cm long leaf held 33.34 cm from the lens. Calculate the image height, h_i, in cm, including the correct sign (+ for upright, - for inverted).

A WCU student, who is snowboarding at Cataloochee, slides horizontally off the ledge of snowbank that is 1.25 meters above the ground.   When she leaves the ledge, she is initially moving horizontally at 7.50 m/s. Ignore air friction, as usual.

1. Make a table showing values of x, y, v_x, v_y, and v_total from the beginning (t = 0) to end (you’ll have to figure out t_final) of her path for every 0.0200 seconds. (Note that she will hit the ground, y = 0, at the end.)

2. Plot a graph of the snowboarder’s position during this whole time. (That is, plot her y vs. x position on one single graph.)

1 point) A truck starts from rest and accelerates at 1?/?² . 6 s later, a car accelerates from rest at the same starting point with an acceleration of 2.7m/s² .

a) Where and when does the car catch the truck?

m from the starting point

at seconds from the moment the truck started to accelerate.

b) What are their velocities when they meet?

The truck : m/s

The car : m/s

explain in simple terms the postulates of the special theory of relativity

A 7.0-kg rock at a temperature of 30°C is dropped into a shallow lake at 30°C from a height of 1.0×10^5 m. What is the resulting change in entropy of the universe? (b) If the temperature of the rock is 100°C when it is dropped, what is the change of entropy of the universe? Assume that air friction is negligible (not a good assumption) and that c=860J/kg·K is the specific heat of the rock.

A certain refrigerator has a COP of 5.00. When the refrigerator is running, its power input is 500 W. A sample of water of mass 500 g and temperature 20.0 ºC is placed in the freezer compartment. How long does it take to freeze the water to ice at 0ºC?ANS = 83.3 s

I can't seem to get 83.3s

True or False

Determine if the following statements are true or false.

_____ 1. A liquid takes the volume of its container.

_____ 2. Particles of amorphous solids have no definite pattern.

_____ 3. A beef steak is an example of a crystalline solid.

_____ 4. Viscosity causes water to curve upward at the top rim of a glass.

_____ 5. There is more gas than any other state of matter in the universe.

_____ 6. All states of matter have a fixed mass and fixed volume.

_____ 7. The volume and shape of a solid can never change.

_____ 8. Surface tension explains why water forms droplets.

_____ 9. Water has greater viscosity than any other liquid.

_____ 10. A gas spreads out to fill all available space.

Matching

Match each definition with the correct term.

A 4.9-m-wide swimming pool is filled to the top. The bottom of the pool becomes completely shaded in the afternoon when the sun is 22 ∘ above the horizon.

Write a few lines about: Fluids, Density, Pressure, change of Pressure with Depth in a liquid (water) and Archimedes’ Principle. What the SI units on each of them and give some practical example of each of them.

A cement block accidentally falls from rest from the ledge of a 51.7-m-high building. When the block is 18.7 m above the ground, a man, 2.00 m tall, looks up and notices that the block is directly above him. How much time, at most, does the man have to get out of the way? Number Units

An object is 1.6 m to the left of a lens of focal length 0.6 m. A second lens of focal length -4 m is 0.58 m to the right of the first lens. Find the distance between the object and the final image formed by the second lens.

____ m

What is the overall magnification (with sign)?

Is the final image real or virtual?

Is it upright or inverted?