A set of jumper cables used to start a car from another car's battery is connected to the terminals of both batteries.  

If 20 A of current exists in the cables during the starting procedure and the cables are parallel and 20 cm apart, do the wires repel or attract?

If 20  of current exists in the cables during the starting procedure and the cables are parallel and 20  apart, do the wires repel or attract?

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Part B

Explain.

Essay answers are limited to about 500 words (3800 characters maximum, including spaces).

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Part C

What is the magnetic field strength that each wire produces at the location of the other?

Express your answer using two significant figures.

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Part D

What is the force per unit length on the cables?

Express your answer using two significant figures.

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A helicopter propeller blade starts from rest and experiences a constant angular acceleration of 14.0 rad/s2. Find the speed of a point on the blade 5.60 m from the axis of rotation when the blade has completed 13 revolutions.

A uniform ladder 5.30  m long rests against a frictionless, vertical wall with its lower end 3.10  m from the wall. The ladder weighs 157  N . The coefficient of static friction between the foot of the ladder and the ground is 0.430. A painter weighing 739  N climbs slowly up the ladder.

How far along the ladder can the painter climb before the ladder starts to slip?

If it should happen that a high voltage electric line should drop from the pole and make contact with a car, the person in the car should jump out of the car with both feet at the same time, rather than stepping out, one foot at a time. Explain the rationale behind this safety tip.

The hollow cylinder from the last problem is attached to a spring with spring constant k = -1.6 and extended to an initial displacement of 9 cm

A) What is the period if it takes 20 s to travel to a point halfway between the 1st equilibrium point and the negative extreme displacement?

B) What is the displacement 7 s later?

C) What is the velocity at this point?

D) What is the acceleration?

We can roughly model a gymnastic tumbler as a uniform solid cylinder of mass 65.0 kg and diameter 1.00 m.

Part A If this tumbler rolls forward at 0.300 rev/s , how much total kinetic energy does he have?

Part B What percent of his total kinetic energy is rotational?

7.3 Steam Generator Tube Break

(c) What particular precautions would need to be followed while shutting down such a unit?

Steam at 100°C is added to ice at 0°C.

(a) Find the amount of ice melted and the final temperature when the mass of steam is 11 g and the mass of ice is 49 g.

(b) Repeat with steam of mass 2.0 g and ice of mass 49 g.

(a) A 374 kg satellite orbits the Earth at a height of 3197 km above the Earth's surface. Assume the Earth has a mass of 5.98 x 10²⁴ kg and a radius of 6,380 km. Find the velocity (in m/s) of the satellite in its orbit.

(b) Calculate the period of the satellite's orbit when it orbits the Earth at a height of 3197 km above the Earth's surface. State your answer in minutes.

The angular momentum of a flywheel having a rotational inertia of 0.407 kg·m² about its central axis decreases from 5.40 to 0.970 kg·m²/s in 4.60 s. (a) What is the magnitude of the average torque acting on the flywheel about its central axis during this period? (b) Assuming a constant angular acceleration, through what angle does the flywheel turn? (c) How much work is done on the wheel? (d) What is the magnitude of the average power done on the flywheel?

A damped oscillator is formed by attaching a mass with m = 1.5 kg to one end of a spring with spring constant k = 8 N/m. The other end of the spring is anchored and the mass can slide on a horizontal surface The damping force is given by –bv with b = 230 g/s. At t=0, the mass is displaced so that the spring is compressed by 12 cm from its unstretched length and released from rest.

(a) Find the time required for the amplitude of the resulting oscillations to decay to 1/3 of its initial value.

(b) How many oscillations are made by the mass during this time?

(c) Find the value of b so that the oscillator is critically damped.

(d) At t=0, this critically damped oscillator is displaced so that the spring is stretched a distance of 12 cm beyond its unstretched length, find the time required for mass to reach the position for which the spring is stretched by only 4 cm.

•A ball is thrown upward from an initial height of   4.9 m with an initial speed of 9.8 m/s

•How high is the ball 2.0 s later?

•What is the velocity of the ball at its highest point

•When does it reach Its highest point

•How high does the ball go?

•When does the ball hit the ground?

•How fast is it going when (right before) it hits the ground?

Bohr’s Model can be used to find the wavelengths of the photons in the absorption or emission spectrum of hydrogen atom.

Using that model, find the wavelengths of the 5→2, 4→2, 3→2 and 2→1 transitions. Specify the colour associated with these wavelengths when possible. To determine the colours, use tables. If the wavelength is not part of the visible spectrum, specify if it is ultraviolet or infrared.

The propeller of a plane has a rotational inertia of 890 kg*m². Each blade has a length of 3.3 m. The propellor starts from rest and reaches a final angular speed of 16 rad/s in only 8 seconds.

a) What was the angular acceleration of the propeller?

b) What was the net torque exerted on the propeller while it was accelerating?

c) When t = 4 s, what was ω for the propeller?

d) When t = 4 s, through what angle θ had the propeller rotated? Your answer should be entered in radians.

e) When t = 4 s, determine a_c for the tip of a blade.

f) When t = 4 s, determine a_tan for the tip of a blade.

g) When t = 4 s, determine a_tot for the tip of a blade.

Thank you for your help!

how do you calculate the TOTAL energy that is released during thermal fission, of the reaction 235U+1n--->140Ba+98Kr+2n. Emphasis on total, meaning prompt and delayed neutron energy should be taken into account.