A transverse sinusoidal wave on a string is moving in the −x-direction. Its speed is 30.0 m/s, and its period is 20.0 ms. At t = 0, a colored mark on the string at x = 0 has a vertical position of 2.00 cm and is moving down with a speed of 1.30 m/s. (a) What is the amplitude of the wave (in m)? 0.0204 Correct: Your answer is correct. m (b) What is the phase constant (in rad)? Incorrect: Your answer is incorrect. Use the expressions you wrote for y and vtransverse from part (a), and divide them to find an equation for tan(ϕ). Take the inverse to find ϕ. Note that the angle you are looking for is in the second quadrant, so you will need to modify your calculator answer as needed. rad (c) What is the maximum transverse speed of the string (in m/s)? m/s (d) Write the wave function for the wave. (Use the form A sin(kx + ωt + ϕ). Assume that y and x are in m and t is in s. Do not include units in your answer.) y(x, t) = m

1. A 1.5- volt battery is connected across an LED bulb, but the bulb does not “light up.” What are two possible reasons why it’s not lighting? (Both the battery and LED are in working order,)

2. ) In what way are an LED and a solar cell alike? In what ways are they different

Please explain everything in detail, I have a lot of difficulty with science. Thank you!

A 2.0-kg ball moving at 10 m/s makes an off-center collision with a 3.0-kg ball that is initially at rest. After the collision, the 2.0-kg ball is deflected at an angle of 30° from its original direction of motion and the 3.0-kg ball is moving at 4.0 m/s. Find the speed of the 2.0-kg ball and the direction of the 3.0-kg ball after the collision.
Hint: sin²θ + cos²θ = 1.

Lions can run at speeds up to approximately 80.0 km/h. A hungry 106 kg lion running northward at top speed attacks and holds onto a 37.5 kg Thomson's gazelle running eastward at 77.5 km/h.

Find the final speed ?f of the lion‑gazelle system just after the lion attacks.

Find the angle ?θ between the final velocity of the lion‑gazelle system and the East axis, with positive angles measured counterclockwise from the East axis.

An old Biblical story tells of David, a small warrior engaged in man-to-man combat with Goliath, a much larger adversary. In the story, David uses a sling to increase the speed of a projectile (in this case a rock), striking Goliath in the forehead and killing him. The type of sling often used in such combat consists of a long strip of cloth with a pouch halfway down its length. The rock is positioned in the pouch, with the warrior holding both ends of the sling. By whirling the sling in a horizontal* circle, a warrior can release one end of the sling, therefore allowing the projectile to fly in a straight line at high speed. In this problem, we will assume that the sling, when unfolded, was roughly 5.12 feet in total length. We will also assume the rock weighed a half a pound. If David whirled the sling to the point where the sling subtended an angle of θ = 3.93o with the horizontal, with what speed did the rock strike Goliath? (Assume no air friction and that the drop in height due to gravity is minimal.)

speed rock struck Goliath = ______ mph

A typical break shot in pool (the opening shot) is about 20 mph with a ball that is about half the weight of the rock in the story. Considering this, what impact do you think a half-pound rock traveling at the above calculated speed would have on someone if struck in the forehead?

-a- The impact would hurt a little but would likely not cause any injury.

-b- The impact would likely cause serious injury.

Suppose David had missed. How far would the rock travel before striking the ground if David released it from a height of 4.25 ft? (Assume no air friction.)

A rod of length 22.00 cm has linear density (mass per length) given by

λ = 50.0 + 16.0x

where x is the distance from one end, and λ is measured in grams/meter.

(a) What is its mass? _______________g

(b) How far from the x = 0 end is its center of mass? ________________m

gedananken-experiment. explain thebehavior of a yo-yo in terms of conservation of mechanical energy

A wind turbine is initially spinning at a constant angular speed. As the wind's strength gradually increases, the turbine experiences a constant angular acceleration 0.116 rad/s2. After making 2870 revolutions, its angular speed is 124 rad/s. (a) What is the initial angular velocity of the turbine? (b) How much time elapses while the turbine is speeding up?

4. A boy stands on a diving board and tosses a stone into a swimming pool. The stone is thrown from a height of 2.8 m above the water surface with a velocity of 5.6 m/s at 72 degrees above the horizontal.

a) First determine the time it is airborne. (I got 1.48 sec)

b) Now find its impact velocity. (Vx=2 m/s and Vy=9.17 m/s)

As the stone impacts the water, it instantly slows down to half its previous velocity, and maintains that velocity (both speed and direction) as it sinks to the bottom of the pool, which is 4.0 m deep.

c) Find the time it takes to reach the bottom. (1.93 sec)

Bonus +3 What is the total horizontal displacement of the stone over its entire trip? I dont know how to do this one

how does an intensifying screen work and what does it do? The goal is to be able to understand what the question is asking, be able to understand the answer, and also use your own words as much as possible

A single-turn square loop of wire, 2.00 cm on each edge, carries a clockwise current of 0.160 A. The loop is inside a solenoid, with the plane of the loop perpendicular to the magnetic field of the solenoid. The solenoid has 30.0 turns/cm and carries a clockwise current of 15.0 A.

(1) Find the force on each side of the loop.

magnitude:____________________uN

direction: a) the force is zero b) directed towards the center c) directed away from the center

(2) Find the magnitude of the torque acting on the loop.

___________________ N

Understand and be able to state the followings:

• Archimedes’ Principle• Pascal’s Principle
• Bernoulli’s Principle• Hooke’s Law

• Newton’s Law of Cooling
• First Law of Thermodynamics
• Second Law of Thermodynamics

A 1.0-cm-tall object is 100 cm from a screen. A diverging lens with focal length -20 cm is 20 cm in front of the object.

a. What is the focal length of a second lens that will produce a well-focused, 2.0-cm-tall image on the screen?

b. What is the distance from the screen of the second lens?

You take your trusty 120 turn solenoid, with 20 cm diameter and spin it at a rate of 10 times per second in a magnetic field that you have constructed with two gigantic neodymium magnets, creating a uniform magnetic field. You are spinning the solenoid so that its rotation axis is perpendicular to the magnetic field direction.

a) What field strength do you need to create a peak emf voltage of 150 V? (Hint: use flux as a function of angle.)

b) What orientation must the solenoid be in to achieve peak emf?

Can someone please explain rotational motion?