A stunt pilot in an air show performs a loop-the-loop in a vertical circle of radius 3.80* 10^3 m. During this performance the pilot whose weight is 644 N, maintains a constant speed of 2.05 *10^2 m/s.

(a) When the pilot is at the highest point of the loop determine his apparent weight in N.

(b) At what speed, in m/s, will the pilot experience weightlessness?

(c) When the pilot is at the lowest point of the loop determine his apparent weight in N. N

Please answer the questions fully and dont copy what was answered earlier on a previous post please

Lab 21 Part 1:

Materials- Slinky, Partner

Methods- A slinky was spread out 15 feet long with a partner and I sitting on the floor. Each of us was only holding a couple of coils while the rest was on the ground. Then each person sent over waves of different sizes and observed the different speeds that they passed by. Afterwards each person sent over transverse waves by moving the slinky side to side. Then we observed longitudinal waves by pushing the slinky in and pulling back.

            After that the partner sent a transverse wave and the same time as me. It was observed what happens when the waves pass each other. Then moving waves were made by moving one end of the slinky back and forth while the partners end was still to create standing waves.

1. What happened when the transverse waves reached your partner’s end? Did the reflected wave stay on the same side as the one you sent? Draw a diagram showing the incoming and reflected waves. 2. Did the waves go any faster or slower when you tried a variety of amplitudes? Explain how this agrees or disagrees with the equation for a transverse wave’s velocity. 3. What did you notice about the speed of the longitudinal waves compared to the transverse waves? 4. Explain what happened when you and your partner both sent waves on the same side. What kind of interference took place? 5. What happened when waves on opposite sides passed each other? 6. How did shortening the length of the spring affect the resonant frequencies? How does this confirm the relationship v = λ f when velocity is constant? (Hint: a shorter spring length means smaller wavelengths for each standing wave). 7. Using this knowledge, explain how musical instruments create higher and lower tones. Use a string instrument as an example.

An instrument used to measure the airspeed on many early low-speed airplanes was a venturi duct with a convergent-divergent duct (the front section's cross sectional area decreases in the flow direction, and the back section's cross sectional area increases in the flow direction. There is a "throat" in which the area is minimum.). Let A1 and A2 denote the inlet and throat areas, respectively. Let P1 and P2 denote the pressure at the inlet and throat, respectively. If the area ratio is A2/A1 = 1/4 and P1 - P2 = 80 lb/ft2. If the aircraft is flying at standard sea level, what is the velocity in knots?

Explain in less than 4 brief sentences how a Tesla coil works. Add a sketch.

An ancient wooden club is found that contains74g of carbon and has an activity of 7.7 decays per second.

Determine its age assuming that in living trees the ratio of 14C/12Catoms is about 1.3

A soccer player kicks a lock horizontally of a 46 m high cliff into a pool of water. If the player hears the sound of the splash 3.26 s later, (a)what was the initial speed given to the rock in m/s?assume a speed of sound in air is 343 m/s. (b)What if the temperature near the cliff suddenly falls to 0ﾟ C reducing the speed of sound of 331 m/s, what would the initial speed of the rock have to be in m/s for the soccer player to hear the sound of the splash 3.26 s after kicking the rock?

6. In each situation described below, compare the magnitudes of the two forces. Explain your answer in each case.

g. A truck attempts to tow a car. They are connected by a 2-m-long rope. At first the truck doesn’t pull hard enough, and the car doesn’t move. Compare the force exerted by the truck’s bumper on the rope to that exerted by the rope on the truck’s bumper. Also compare the force exerted by the rope on the car’s bumper to that exerted by the car’s bumper on the rope.

h. Finally the truck pulls hard enough so that the car begins to move. Compare the same pairs of forces as in (g) to each other.

i. An elevator is hanging from a strong cable. The elevator is at rest. Compare the force exerted by the cable on the elevator to that exerted by the elevator on the cable.

j. In (i) compare the tension in the cable to the weight of the elevator.

k. The elevator in (i) begins accelerating upward. Now compare the force exerted by the cable on the elevator to that exerted by the elevator on the cable.

l. In (k) compare the tension in the cable to the weight of the elevator.

m. The elevator in (i) is moving upward at a constant velocity. Now compare the force exerted by the cable on the elevator to that exerted by the elevator on the cable.

n. In (m) compare then tension in the cable to the weight of the elevator.

The potential difference from the cathode (negative electrode) to the screen of an old television set is +22,000 V. An electron leaves the cathode with an initial speed of zero.

a)Determine the kinetic energy of the electron.

b)Determine the speed of the electron.

Chuck and Jackie stand on separate carts, both of which can slide without friction. The combined mass of Chuck and his cart, mcart, is identical to the combined mass of Jackie and her cart. Initially, Chuck and Jackie and their carts are at rest. Chuck then picks up a ball of mass mball and throws it to Jackie, who catches it. Assume that the ball travels in a straight line parallel to the ground (ignore the effect of gravity). After Chuck throws the ball, his speed relative to the ground is vc. The speed of the thrown ball relative to the ground is vb. Jackie catches the ball when it reaches her, and she and her cart begin to move. Jackie's speed relative to the ground after she catches the ball is vj. When answering the questions in this problem, keep the following in mind: The original mass mcart of Chuck and his cart does not include the mass of the ball. The speed of an object is the magnitude of its velocity. An object's speed will always be a nonnegative quantity.

Discuss the discoveries that LIGO has made. Why are these discoveries considered to be direct detection of gravitational waves?

A smooth circular hoop with a radius of 0.600 m is placed flat on the floor. A 0.450-kg particle slides around the inside edge of the hoop. The particle is given an initial speed of 9.50 m/s. After one revolution, its speed has dropped to 4.50 m/s because of friction with the floor.

(a) Find the energy transformed from mechanical to internal in the particle—hoop—floor system as a result of friction in one revolution.

_____J

(b) What is the total number of revolutions the particle makes before stopping? Assume the friction force remains constant during the entire motion.

_____rev

An attacker at the base of a castle wall 3.75 m high throws a rock straight up with speed 8.50 m/s from a height of 1.50 m above the ground.

(a) Will the rock reach the top of the wall?

(b) If so, what is its speed at the top? If not, what initial speed must it have to reach the top?

(c) Find the change in speed of a rock thrown straight down from the top of the wall at an initial speed of 8.50 m/s and moving between the same two points.

(d) Does the change in speed of the downward-moving rock agree with the magnitude of the speed change of the rock moving upward between the same elevations?

(e) Explain physically why it does or does not agree.

I tried to ask this question before, but got the wrong answer. I know for a, the answer is yes. I can't figure out the rest. Thanks!

1. Why is the conductivity of metal different from the insulator? - How different is the semiconductor from them?

2. What is the main cause of the energy gap? How is it related to the Bragg condition.

3. How is Bloch function different from the general wavefunction?

What do you think a dream yard for kids? What would they like to do there? What kinds of things should this yard have? Why? Explain your thoughts.