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.

Two cars are on a level air track. They have the same mass as each other. The red car is given a push so that it moves toward the blue car with an initial speed of 2 m/s, while the blue car is given a push so that it moves toward the red car with an initial speed of 4 m/s. If the cars completely stick together, find their combined speed after the collision.

2.

This is an inelastic collision, so some energy must be lost. Find how much, and suggest where it could have gone.

A 63.0-kg survivor of a cruise line disaster rests atop a block of Styrofoam insulation, using it as a raft. The Styrofoam has dimensions 2.00 m ✕ 2.00 m ✕ 0.0895 m. The bottom 0.023 m of the raft is submerged.

(a) Draw a force diagram of the system consisting of the survivor and raft.

(b) Write Newton's second law for the system in one dimension, using B for buoyancy, w for the weight of the survivor, and wr for the weight of the raft. (Set a = 0. Solve for Fy, the y-component of the net force. Let upward be the positive y-direction.)

(c) Calculate the numeric value for the buoyancy, B. (Seawater has density 1025 kg/m3. Enter answer to at least the ones digit.)

(d) Using the value of B and the weight w of the survivor, calculate the weight wr of the Styrofoam.

(e) What is the density of the Styrofoam? (f) What is the maximum buoyant force, corresponding to the raft being submerged up to its top surface?

(g) What total mass of survivors can the raft support?

An electron in a TV camera tube is moving at 6.20×106 m/s in a magnetic field of strength 75 mT. Without knowing the direction of the field, what can you say about the greatest and least magnitude of the force acting on the electron due to the field? Maximum force? Minimum force? At one point the acceleration of the electron is 7.767×1016 m/s2. What is the angle between the electron velocity and the magnetic field? (deg)