A small bouncy ball is dropped from the flat roof of an abandoned, and as-yet unrepurposed industrial building. The ball is observed to take 1/8 of a second to fall across a broken window with the total height of 1.2m. After the ball hits the ground, it bounces back upward and again traverses the window’s height in 1/8s of a second on its way toward the top of the roof. We thus assume that the ball loses no energy upon impact with the ground. If the time that the ball spends below the bottom of the window is 2s, answer the following questions.

a) What is the velocity of the ball at the top and bottom of the window, respectively, when the ball is on its way down?

(b) What is the time it takes the ball to fall from the top of the building to the top of the window?

(c) What is the height of the building?

A pilot flies her route in two straight-line segments. The displacement vector A for the first segment has a magnitude of 235 km and a direction 30.0^o north of east. The displacement vector B for the second segment has a magnitude of 173 km and a direction due west. The resultant displacement vector is R = A + B and makes an angle θ with the direction due east. Using the component method, find (a) the magnitude of R and (b) the directional angle θ.

Three equal point charges, each with charge 1.30μC , are placed at the vertices of an equilateral triangle whose sides are of length 0.300m . What is the electric potential energy U of the system? (Take as zero the potential energy of the three charges when they are infinitely far apart.)

A 45.0-kg girl is standing on a 159-kg plank. The plank, originally at rest, is free to slide on a frozen lake, which is a flat, frictionless surface. The girl begins to walk along the plank at a constant velocity of 1.58 m/s to the right relative to the plank. (Let the direction the girl is moving in be positive. Indicate the direction with the sign of your answer.)

(a) What is her velocity relative to the surface of ice?
m/s

(b) What is the velocity of the plank relative to the surface of ice?
m/s

A spider hangs from a strand of silk whose radius is 4.0 X 10 E-6 m. The density of the silk is 1300 kg/m3(cube). When the spider moves, waves travel along the strand of silk at a speed of 280 m/s. Ignore the mass of the silk strand, and determine the mass of the spider.

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A steel ball with a mass of 0.600 kg is dropped from an initial height of 2.80 m onto a metal plate. The steel ball bounces multiple times and on each bounce it returns to 75% of its previous maximum height.

A)What is the initial mechanical energy of the ball-Earth system, just after the ball is released from its initial height? Use the surface of the steel plate as the y = 0 reference point for the gravitational potential energy.

B)How much mechanical energy does the system lose during its first bounce?

What are differences (in use, benefits, requirements etc) in the 160 volts that the USA uses and 220-240 volts the rest of the world uses? Explain how a step-down converter/transformer to reduce the voltage input and outputs the correct voltage works when using a device of 240 volts to the USA 160v, vice versa?

A coin is dropped from a hot-air balloon that is 287.3m above the ground and rising at 10.0m/s upward. For the coin, find: a) the maximum height reached,b) its position 4.34s after being released,c) and the time before it hits the ground.

Data for Experiment 108- Frequency of Vibration

Frequency and Tension

                                                            Trial 1                         Trial 2

Vibrating Length (L)                               50 cm                         65 cm                    

Number of Segments (n)                           2                                  2

Attached Mass (m)                                  70g                              90g

Linear Mass Density                             0.0015 g/cm             0.0015 g/cm

Actual Frequency                                   120 Hz                         120 Hz

Find the Following. Use the correct number of Significant Figures.

1. Tension ( T=mg) in Trial 1 and Trial 2

2. Experimental Frequency in both trials.

3. Percentage error in both trials.

A person travels by car from one city to another with different constant speeds between pairs of cities. She drives for 50.0 min at 70.0 km/h, 13.0 min at 70.0 km/h, and 35.0 min at 30.0 km/h and spends 50.0 min eating lunch and buying gas. (a) Determine the average speed for the trip. km/h (b) Determine the distance between the initial and final cities along the route. km Viewing Saved Work Revert to Last Response

A 8.0-cm-diameter disk emits light uniformly from its surface. 20 cm from this disk, along its axis, is an 9.0-cm-diameter opaque black disk; the faces of the two disks are parallel. 20 cm beyond the black disk is a white viewing screen. The lighted disk illuminates the screen, but there�s a shadow in the center due to the black disk. What is the diameter of the completely dark part of this shadow?

A person pushes a 14.6-kg shopping cart at a constant velocity for a distance of 26.8 m on a flat horizontal surface. She pushes in a direction 26.8 ° below the horizontal. A 39.0-N frictional force opposes the motion of the cart. (a) What is the magnitude of the force that the shopper exerts? Determine the work done by (b) the pushing force, (c) the frictional force, and (d) the gravitational force.

Any tips on how to learn Quantum Mechanics effectively?

A simple pendulum with mass m = 1.8 kg and length L = 2.69 m hangs from the ceiling. It is pulled back to an small angle of θ = 8.7° from the vertical and released at t = 0.

1) What is the period of oscillation?

2) What is the magnitude of the force on the pendulum bob perpendicular to the string at t=0?

3) What is the maximum speed of the pendulum?

4) What is the angular displacement at t = 3.65 s? (give the answer as a negative angle if the angle is to the left of the vertical)

5) What is the magnitude of the tangential acceleration as the pendulum passes through the equilibrium position?

6) What is the magnitude of the radial acceleration as the pendulum passes through the equilibrium position?

7) Which of the following would change the frequency of oscillation of this simple pendulum?

increasing the mass

decreasing the initial angular displacement

increasing the length

hanging the pendulum in an elevator accelerating downward

Two cylindrical iron rods both at temperatureThave lengthsLand 2L, and radiiRandR/2, respectively. If the rods’ temperatures are raised to 3T, and forces are appliedto prevent the rods from changing length, what is the ratio of the forces on the tworods?