A 3.0-cm-diameter, 14-turn coil of wire, located at z = 0 in the xy-plane, carries a current of 7.5 A. A 2.0-mm-diameter conducting loop with 2.0× 10^−4 Ω resistance is also in the xy-plane at the center of the coil. At t = 0 s, the loop begins to move along the z-axis with a constant speed of 75 m/s.

What is the induced current in the conducting loop at t = 200 μs? The diameter of the conducting loop is much smaller than that of the coil, so you can assume that the magnetic field through the loop is everywhere the on-axis field of the coil.

In class we learned about Kate, a bungee jumper with mass ? = 50.0 kg who jumps off a bridge of height ℎ = 25.0 m above a river. After she jumps, the bungee cord – which behaves as an ideal spring with spring constant ? = 28.5 N/m – stretches to a new equilibrium with length ?? = 20.0 m (since this is the new equilibrium, let us refer to it as ? = 0 in Hooke’s law and in the elastic potential energy). Note that I have changed the numbers a bit from the ones in class.
After hanging out at this new equilibrium for a bit, Kate starts to get worried. She yells up to her friend Ken, who is frantically trying to figure out how to hoist her back up. After a couple of hours of this, Kate starts to get hungry. She begs Ken to throw her down a backpack full of provisions with mass ? = 15.0 kg. Ken complies, dropping the bag from the bridge with no initial velocity. Throughout this problem you may neglect all sources of friction or other non-conservative forces.

a) Kate catches the bag when it gets to her. What are the momenta of Kate and the bag just before she catches it? What about after?

b) What is the total energy of Kate plus the bag before and after the collision? Is energy conserved during the process of catching the bag?

c) After Kate catches the bag, the bungee cord starts to stretch. What is her downward speed when she hits the river?

d) Sensing her impending doom, Kate thinks fast and strips off her heavy winter coat, which has a mass of 2.00 kg. Just before she's about to go into the river, she throws the coat downward with all her might. With what speed must she throw the coat to avoid drowning?

A shot-putter throws the shot with an initial speed of 11.2 m/s from a height of 5.00 ft above the ground. What is the range of the shot if the launch angle is (a) 24.0 ∘ , (b) 30.0 ∘ , (c) 42.0 ∘ ?

A spring is attached to an inclined plane as shown in the figure. A block of mass m = 2.75 kg is placed on the incline at a distance d = 0.294 m along the incline from the end of the spring. The block is given a quick shove and moves down the incline with an initial speed v = 0.750 m/s. The incline angle is θ = 20.0°, the spring constant is k = 450 N/m, and we can assume the surface is frictionless. By what distance (in m) is the spring compressed when the block momentarily comes to rest?

Ideal vs real battery

a. An ideal battery doesn't exist, are all batteries real?

b. Is the chemical reaction the reason why there is internal resistance?

c. When learning ohms law why to use examples of ideal batteries?

We often think about two-dimensional motion in terms of a projectile, like someone throwing a ball up in the air. Consider, instead, the surface of an air-hockey table, where the puck travels horizontally from one end of the table to the other. Imagine you’re standing at one end of the table and answer the following questions in your initial post to the discussion.

1. Describe the shape of the puck’s path, starting from the end of the table where you’re standing, as it undergoes the following types of motion:
   1. acceleration in the x-direction
   2. acceleration in the y-direction
   3. constant velocity in the x-direction with acceleration in the negative y-direction
2. What must be true of x-velocity and y-velocity for the puck to travel at a 45-degree angle?
3. How can you make the angle steeper or shallower?
4. Can the puck follow a straight path if it’s accelerating in one or both directions? Choose your own orientation for the coordinate system.

(a) Suppose a meter stick made of steel and one made of invar are the same length at 0°C. What is their difference in length at 21.5°C? The coefficient of thermal expansion is 12 ✕ 10−6/°C for steel and 0.9 ✕ 10−6/°C for invar.

(b) Repeat the calculation for two 20.5-m-long surveyor's tapes.

Please answer for college physics discussion post. Please only type out the response as when writing it and uploading it is difficult to read. Thanks!

Respond to the following in detail:

• In your own words, explain angular momentum, moment of inertia, and torque. Also give examples.

1. White dwarfs are not included in the luminosity classification because they are:
a) no longer producing energy by nuclear reactions
b) too small
c) not yet active stars; they have not yet begun nuclear reactions
d) no longer radiating energy away

2. Absolute magnitude is defined as the apparent magnitude that a star would have if
a) it were located at exactly 10 pc from Earth
b) it were located at exactly 10 AU from Earth
c) all the energy from the star was concentrated in the visual region
d) it were located at exactly 10 ly from Earth

3. What is a dwarf star?
a) main-sequence star
b) a star that is significantly smaller than a giant or supergiant star
c) large, planetary object, such as Jupiter
d) a star of about the same size (diameter) as Earth

If a system feels any external force, must it then by necessity not satisfy conservation of momentum? What if it feels two such external forces that happen to balance? What if it feels two such external forces that happen to balance in just (say) the x-direction but do not balance in (say) the y-direction?

For a system that’s initially at rest (zero initial total momentum and zero initial kinetic energy) but then ends up with multiple objects moving (non-zero final total momentum and non-zero final kinetic energy), what would you have to do to use conservation of mechanical energy in order to determine info about the objects’ velocities?

A potential difference of 53 mV is developed across the ends of a 12.0-cm-long wire as it moves through a 0.27 T uniform magnetic field at a speed of 4.0 m/s. The magnetic field is perpendicular to the axis of the wire.

What is the angle between the magnetic field and the wire's velocity?

How are the properties of magnetic field lines similar to the properties of electric field lines?How are they different? (at least three for each) Thanks for your help.

Work on a sliding crate.

A worker pushes a 47.0 Kg crate across a level horizontal floor by applying a constant force of exactly 150.0 N at an angle of 23.0 degrees below the horizontal. The crate begins at rest and ends 15.0m from where it started traveling at 2.6m/s

A. What is the work done by the applied force as the crate moves across the floor?

B What is the work done by the friction force as the crate moves across the floor?

C. What is the coefficient of kinetic friction [Uk] between the crate and the horizontal plane?