A 1450 kg car begins sliding down a 12.0 ° inclined road with a speed of 34.0 km/h.The engine is turned off, and the only forces acting on the car are a net frictional force from the road and the gravitational force. After the car has traveled 45.0 m along the road, its speed is 50.0 km/h. (a) How much is the mechanical energy of the car reduced because of the net frictional force? (b) What is the magnitude of that net frictional force?

Consult Interactive Solution 21.51 to see how this problem can be solved. A coil rotating perpendicularly to a uniform magnetic field contains 340 turns and has an area per turn of 3.0 × 10^-3 m². The magnetic field is 0.18 T, and the current in the coil is 0.15 A. A brake shoe is pressed perpendicularly against the shaft to keep the coil from turning. The coefficient of static friction between the shaft and the brake shoe is 0.79. The radius of the shaft is 0.0077 m. What is the magnitude of the minimum normal force that the brake shoe exerts on the shaft?

Consider three point charges q1=q2=q3=Q. If q1 and q2 are located on the Y-axis at y=+a and y= -a and the third charge is located at a point x on the X-axis. (a) find the force E exerted by q1 and q2 on q3 when q3 is located at the origin (b) what is the force F on q3 when q3 is located at an arbitrary value of x on the X-axis? (c) for what value of x is the force F on q3 a maximum? Hint. The notation F means that you need to find the magnitude and direction of the electric force.

The magnetic field 38.0 cm away from a long, straight wire carrying current 4.00 A is 2110 nT.

(a) At what distance is it 211 nT?

380 cm

(b) At one instant, the two conductors in a long household extension cord carry equal 4.00-A currents in opposite directions. The two wires are 3.00 mm apart. Find the magnetic field 38.0 cm away from the middle of the straight cord, in the plane of the two wires.

16.6 nT

(c) At what distance is it one-tenth as large?

_______________________cm

(d) The center wire in a coaxial cable carries current 4.00 A in one direction, and the sheath around it carries current 4.00 A in the opposite direction. What magnetic field does the cable create at points outside the cables?
0 nT

Derive the general wavefunction for a particle in a box (i.e. the infinite square well

potential). Go on to normalise it. What energy/energies must the particle have to

exist in this box?

In a location in outer space far from all other objects, a nucleus whose mass is 4.019480 × 10−25 kg and that is initially at rest undergoes spontaneous alpha decay. The original nucleus disappears, and two new particles appear: a He-4 nucleus of mass 6.640678 × 10−27 kg (an alpha particle consisting of two protons and two neutrons) and a new nucleus of mass 3.952926 × 10−25 kg. These new particles move far away from each other, because they repel each other electrically (both are positively charged). Because the calculations involve the small difference of (comparatively) large numbers, you need to keep seven significant figures in your calculations, and you need to use the more accurate value for the speed of light, 2.9979246e8 m/s. Choose all particles as the system. Initial state: Original nucleus, at rest. Final state: Alpha particle + new nucleus, far from each other.

Part 1 (a) What is the rest energy of the original nucleus? (Round your answer to seven significant figures.) J the tolerance is +/-2%

Part 2 (b) What is the sum of the rest energies of the alpha particle and the new nucleus? (Round your answer to seven significant figures.) J the tolerance is +/-2%

Part 3 (c) Did the portion of the total energy of the system contributed by rest energy increase or decrease? decrease The total rest energy is unchanged. increase

Part 4 (d) What is the sum of the kinetic energies of the alpha particle and the new nucleus?

Calculate (in MeV) the binding energy per nucleon for 14N.

Calculate (in MeV) the binding energy per nucleon for 56Fe.

Calculate (in MeV) the binding energy per nucleon for 207Pb.

A resistor of resistance R and a capacitor of capacitance C are connected in series to an EMF of voltage E. A switch is set to the open position and the capacitor is initially uncharged. The switch is then closed. Show that when the capacitor charges that half of the energy drawn from the EMF is dissipated in the resistor and that half of the energy is stored in the capacitor.

A merry-go-round rotates from rest with an angular acceleration of 1.11 rad/s2. How long does it take to rotate through (a) the first 1.85 rev and (b) the next 1.85 rev?

Please include an explanation

A helicopter lifts a 75.0 kg astronaut 14.2 m vertically from the ocean by means of a cable. The acceleration of the astronaut is g/10.
A) How much work is done on the astronaut by the force from the helicopter?
B)How much work is done on the astronaut by the gravitational force on her?
C)Just before she reaches the helicopter, what is her kinetic energy?
D) And just before she reaches the helicopter, what is her speed?

Question 1 (1 point)

We have two very long wires, which are parallel to each other pointing to the right in front of us. The pair of wire is horizontal. The wire closest to us carries a charge per unit length of 1mC/m and the other the opposite charge. The two wires are 1m apart and both move together at 100m/s along the wire to the right. We are looking at what happens in the middle region of the two wires (not the end). For the question pick all the right answers (there can be more than one correct answer).

Is it possible that the two electric and magnetic forces between the wires cancel out?

Question 1 options:

Question 2 (1 point)

We have two very long wires, which are parallel to each other pointing to the right in front of us. The pair of wire is horizontal. The wire closest to us carries a charge per unit length of 1mC/m and the other the opposite charge. The two wires are 1m apart and both move together at 100m/s along the wire to the right. We are looking at what happens in the middle region of the two wires (not the end). For the question pick all the right answers (there can be more than one correct answer).

What is the direction of the electric force between the two wires?

Question 2 options:

Question 3 (1 point)

We have two very long wires, which are parallel to each other pointing to the right in front of us. The pair of wire is horizontal. The wire closest to us carries a charge per unit length of 1mC/m and the other the opposite charge. The two wires are 1m apart and both move together at 100m/s along the wire to the right. We are looking at what happens in the middle region of the two wires (not the end). For the question pick all the right answers (there can be more than one correct answer).

What is the strength of the magnetic force per unit length between the two wires?

Question 3 options:

Question 4 (1 point)

We have two very long wires, which are parallel to each other pointing to the right in front of us. The pair of wire is horizontal. The wire closest to us carries a charge per unit length of 1mC/m and the other the opposite charge. The two wires are 1m apart and both move together at 100m/s along the wire to the right. We are looking at what happens in the middle region of the two wires (not the end). For the question pick all the right answers (there can be more than one correct answer).

What is the direction of the magnetic force between the two wires?

Question 4 options:

Question 5 (1 point)

We have two very long wires, which are parallel to each other pointing to the right in front of us. The pair of wire is horizontal. The wire closest to us carries a charge per unit length of 1mC/m and the other the opposite charge. The two wires are 1m apart and both move together at 100m/s along the wire to the right. We are looking at what happens in the middle region of the two wires (not the end). For the question pick all the right answers (there can be more than one correct answer).

How fast would the speed need to be so that the magnitude of the electric force equals the magnitude of the magnetic force between the two wires?

Question 5 options:

Question 6 (1 point)

We have two very long wires, which are parallel to each other pointing to the right in front of us. The pair of wire is horizontal. The wire closest to us carries a charge per unit length of 1mC/m and the other the opposite charge. The two wires are 1m apart and both move together at 100m/s along the wire to the right. We are looking at what happens in the middle region of the two wires (not the end). For the question pick all the right answers (there can be more than one correct answer).

What is the magnitude of the magnetic field in the middle between the two wires?

Question 6 options:

Question 7 (1 point)

We have two very long wires, which are parallel to each other pointing to the right in front of us. The pair of wire is horizontal. The wire closest to us carries a charge per unit length of 1mC/m and the other the opposite charge. The two wires are 1m apart and both move together at 100m/s along the wire to the right. We are looking at what happens in the middle region of the two wires (not the end). For the question pick all the right answers (there can be more than one correct answer).

What is the electric field magnitude in the middle between the 2 wires?

Question 7 options:

Question 8 (1 point)

We have two very long wires, which are parallel to each other pointing to the right in front of us. The pair of wire is horizontal. The wire closest to us carries a charge per unit length of 1mC/m and the other the opposite charge. The two wires are 1m apart and both move together at 100m/s along the wire to the right. For the question pick all the right answers (there can be more than one correct answer).

What is the direction of the magnetic field half-way between the two wires (in the middle section of the wires)?

Question 8 options:

Question 9 (1 point)

We have two very long wires, which are parallel to each other pointing to the right in front of us. The pair of wire is horizontal. The wire closest to us carries a charge per unit length of 1mC/m and the other the opposite charge. The two wires are 1m apart and both move together at 100m/s along the wire to the right. We are looking at what happens in the middle region of the two wires (not the end). For the question pick all the right answers (there can be more than one correct answer).

What is the electric field direction halfway between the two wires?

Question 9 options:

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Question 1 (1 point)

We have two very long wires, which are parallel to each other pointing to the right in front of us. The pair of wire is horizontal. The wire closest to us carries a charge per unit length of 1mC/m and the other the opposite charge. The two wires are 1m apart and both move together at 100m/s along the wire to the right. We are looking at what happens in the middle region of the two wires (not the end). For the question pick all the right answers (there can be more than one correct answer).

Is it possible that the two electric and magnetic forces between the wires cancel out?

Question 1 options:

Question 2 (1 point)

We have two very long wires, which are parallel to each other pointing to the right in front of us. The pair of wire is horizontal. The wire closest to us carries a charge per unit length of 1mC/m and the other the opposite charge. The two wires are 1m apart and both move together at 100m/s along the wire to the right. We are looking at what happens in the middle region of the two wires (not the end). For the question pick all the right answers (there can be more than one correct answer).

What is the direction of the electric force between the two wires?

Question 2 options:

Question 3 (1 point)

We have two very long wires, which are parallel to each other pointing to the right in front of us. The pair of wire is horizontal. The wire closest to us carries a charge per unit length of 1mC/m and the other the opposite charge. The two wires are 1m apart and both move together at 100m/s along the wire to the right. We are looking at what happens in the middle region of the two wires (not the end). For the question pick all the right answers (there can be more than one correct answer).

What is the strength of the magnetic force per unit length between the two wires?

Question 3 options:

Question 4 (1 point)

We have two very long wires, which are parallel to each other pointing to the right in front of us. The pair of wire is horizontal. The wire closest to us carries a charge per unit length of 1mC/m and the other the opposite charge. The two wires are 1m apart and both move together at 100m/s along the wire to the right. We are looking at what happens in the middle region of the two wires (not the end). For the question pick all the right answers (there can be more than one correct answer).

What is the direction of the magnetic force between the two wires?

Question 4 options:

Question 5 (1 point)

We have two very long wires, which are parallel to each other pointing to the right in front of us. The pair of wire is horizontal. The wire closest to us carries a charge per unit length of 1mC/m and the other the opposite charge. The two wires are 1m apart and both move together at 100m/s along the wire to the right. We are looking at what happens in the middle region of the two wires (not the end). For the question pick all the right answers (there can be more than one correct answer).

How fast would the speed need to be so that the magnitude of the electric force equals the magnitude of the magnetic force between the two wires?

Question 5 options:

Question 6 (1 point)

We have two very long wires, which are parallel to each other pointing to the right in front of us. The pair of wire is horizontal. The wire closest to us carries a charge per unit length of 1mC/m and the other the opposite charge. The two wires are 1m apart and both move together at 100m/s along the wire to the right. We are looking at what happens in the middle region of the two wires (not the end). For the question pick all the right answers (there can be more than one correct answer).

What is the magnitude of the magnetic field in the middle between the two wires?

Question 6 options:

Question 7 (1 point)

We have two very long wires, which are parallel to each other pointing to the right in front of us. The pair of wire is horizontal. The wire closest to us carries a charge per unit length of 1mC/m and the other the opposite charge. The two wires are 1m apart and both move together at 100m/s along the wire to the right. We are looking at what happens in the middle region of the two wires (not the end). For the question pick all the right answers (there can be more than one correct answer).

What is the electric field magnitude in the middle between the 2 wires?

Question 7 options:

Question 8 (1 point)

We have two very long wires, which are parallel to each other pointing to the right in front of us. The pair of wire is horizontal. The wire closest to us carries a charge per unit length of 1mC/m and the other the opposite charge. The two wires are 1m apart and both move together at 100m/s along the wire to the right. For the question pick all the right answers (there can be more than one correct answer).

What is the direction of the magnetic field half-way between the two wires (in the middle section of the wires)?

Question 8 options:

Question 9 (1 point)

We have two very long wires, which are parallel to each other pointing to the right in front of us. The pair of wire is horizontal. The wire closest to us carries a charge per unit length of 1mC/m and the other the opposite charge. The two wires are 1m apart and both move together at 100m/s along the wire to the right. We are looking at what happens in the middle region of the two wires (not the end). For the question pick all the right answers (there can be more than one correct answer).

What is the electric field direction halfway between the two wires?

Question 9 options:

5.) A ballistic pendulum consists of a 10 gram projectile striking and sticking to a 1.5 kg mass. Both objects then rise 2.5 cms. A.) Calculate the velocity of the pendulum and projectile (stuck together) after the collision. B.) Determine the initial speed of the projectile as it hits the 1.5 kg mass. C.) How much non-conservative work was done during the process?

In the figure, a parallel-plate capacitor is being discharged by a current ? = 5.0 ?. The plates are square with edge length
? = 8.0 ??.

1. (a) What is the displacement current ?! and displacement current density ?! (current per unit of area) in the air space between the plates?

2. (b) What is the rate at which the electric field between the plates is changing?

3. (c) What is the value of ? ∙ ?? around the dashed path, where ? = 2.0 ?? and ? =3.0 ???

Problem 1a: Velocity Selector: Show that with the right ratio of electric to magnetic field strength a particle of velocity v will proceed through both fields in a straight line at constant speed (hint: you will need an equation containing v. Also: what does the straight line at constant speed give you?). Assume that the angle of the velocity vector relative to the magnetic field vector is 90 degrees.

b: Show mathematically that the charge magnitude and sign do not matter.

c: Draw and label the electric field vector, the electric force vector, the magnetic field vector, the velocity vector and the magnetic force vector. Hint: start with the two force vectors. They have to add to zero. Then use the vector nature of the Eq = F(E) equation and the right hand rule to get the other vectors.) Assume that the particle is negatively charged. Use into and out of the page vector notation where necessary.

d. Explain in terms of what happens with the force vectors when the charge sign changes to allow a particle of either charge sign pass through the velocity selector at constant velocity v. In other words, explain physically why the particle charge sign makes no difference.

e. Explain in terms of what happens with the force vectors when the charge magnitude changes. In other words, explain physically why the charge magnitude makes no difference in the velocity selector.