A marble rolls off a tabletop 0.70 m high and hits the floor at a point 3.5 m away from the table's edge in the horizontal direction.

(a)

How long (in s) is the marble in the air?

__________________________________________ s

(b)

What is the speed of the marble (in m/s) when it leaves the table's edge?

__________________________________________ m/s

(c)

What is its speed (in m/s) when it hits the floor?

__________________________________________m/s

3. A block on an incline is pushed by a hand. The hand exerts a force on the block parallel to the incline. State whether the specified quantities are positive, negative, or zero. Explain in each case.

a. The block moves up the incline and speeds up.The work done by the hand on the block. The work done by the block on the hand.

b. The block moves down the incline and speeds up (even though the hand is still pushing up along the incline.) The work done by the hand on the block. The work done by the block on the hand.

c. The block moves down the incline and slows down. (Note that the hand is now pushing down the ramp, and the ramp has friction.) The work done by the hand on the block. The work done by the block on the hand.

Consider an L-R circuit as shown in the figure. (Figure 1) The battery provides 12.0V of voltage. The inductor has inductance L, and the resistor has resistance R = 150? . The switch is initially open as shown. At time t=0, the switch is closed. At time tafter t=0 the current I(t) flows through the circuit as indicated in the figure.

Part C

What is the current reading I(?) given by the ammeter shown in the circuit (Figure 4) at one time constant after t=0?

Express your answer in amperes.

A spring is compressed by 15 cm, which requires 150 N of force. What is the spring constant of the spring? How much potential energy is stored in the spring? A 20 kg box is attached to the spring. This arrangement is placed such that the spring is horizontal and the box will slide along a frictionless, horizontal track. What is the maximum speed of the box after the spring is released?

explain electromagnetic induction, Faraday's Law, and inductance. Also give examples.

PLEASE DO NOT WRITE IT BY HAND.

Thanks

1) Consider a soap bubble with radius, r. The pressure inside the bubble must be greater than the pressure outside of the bubble. The surface tension of the bubble, y, supports the difference in pressure, delta p. Using dimensional analysis, formulate an expression for the pressure difference.

2) In 1945 the first atomic bomb was tested in New Mexico. The destructive power (Energy) of the bomb was kept classified however, following the release of *time* stamped pictures showing the bomb's explosion *radius* a British physicist, G. I. Taylor, was able to estimate the power released by the explosion. Identify the missing parameter and use dimensional analysis to formulate an expression for the Energy.

A laser beam enters a 19.0 cm thick glass window at an angle of 39.0° from the normal. The index of refraction of the glass is 1.50. At what angle from the normal does the beam travel through the glass? Tries 0/20 How long does it take the beam to pass through the plate?

A solid nonconducting sphere of radius R = 5.7 cm has a nonuniform charge distribution of volume charge density ρ = (14.4 pC/m3)r/R, where r is radial distance from the sphere's center. (a) What is the sphere's total charge? What is the magnitude E of the electric field at (b) r = 0, (c) r = R/2.0, and (d) r = R?

A 56 g ice cube at -57°C is placed in a lake whose temperature is 33°C. Calculate the change in entropy of the cube-lake system as the ice cube comes to thermal equilibrium with the lake. The specific heat of ice is 2220 J/kg·K. (Hint: Will the ice cube affect the temperature of the lake?)

. In a device (figure 30-6) that is used to measure the maximum kinetic energy of photoelectric effect electrons, the voltage difference between the collector and emitter is increased until the current flowing through the circuit goes to zero. This is called the stopping potential and the KEmax can be very simply calculated if you use electron-volts. Using this device, you measure this voltage to be 0.710 V for electrons emitted from a surface illuminated by 492-nm light. Then, when you change the incident light to a new wavelength value, the new voltage is 1.41 V. a)What is the new wavelength? b) What is the work function for the surface?

an electron is moving with a speed of 2.9E5 m/s when it moves in the positive x direction, it feels no force. When it moves in the positive y direction it experiences a force of 3.3E-14N that points in the negative z direction. What is the magnitude and direction of the magnetic field?

Explain how an electric motor works. How does a stereo speaker use an electromagnet to produce sound? (10pts)

Due to the Doppler effect, a moving aircraft sees the broadcast signals at 377 MHz from a stationary communications antenna that broadcasts signals at 356 MHz. Find the relative velocity between the aircraft and the broadcast station. Determine the direction of the moving aircraft.

Speed amplifier. In the figure block 1 of mass m₁ slides along an x axis on a frictionless floor at speed 0.568 m/s. Then it undergoes a one-dimensional elastic collision with stationary block 2 of mass m₂ = 0.284 m₁. Next, block 2 undergoes a one-dimensional elastic collision with stationary block 3 of mass m₃ = 0.522 m₂. (a) What then is the speed of block 3? Compute ratios of (b) speeds, (c) kinetic energies, and (d) momentums for block 3 to block 1.