Other Physics Answers

Q1: If a person could not digest food anymore, what would probably happen to that person? Why?

a) the person would gain weight because the undigested food would sit in the person's body.

b) the person would not lose or gain weight, but it would take longer for the body to use the food that was eaten

c) the person would lose weight because most of the food could not be used by the body

d) nothing would change because digestion does not affect the way food is used by the body.

The standing wave on a string is given by the equation y = (0.08 m) sin[120x] cos[150t].

Find

(a) the component waves whose superposition gives this standing wave.

(b) The wavelength and frequency of the standing wave.

(c) The length of the string if 4 nodes and 3 antinodes are formed.

(d) The transverse velocity of the particle of the string at x = 0.04 m and at t = 2 ms.

Consider two identical interfering waves with wavelength λ = 0.4 m travelling in the positive x-direction. The two waves start at the same time but at different positions, x1 and x2 from an observer (x1 > x2). What should the path difference, ∆x = x1 - x2, between the starting positions be in order for the two waves to differ in phase by π/6 rad?

A standing wave is set up on a string of length L, fixed at both ends. If 6 nodes and 5 antinodes are observed when the wavelength is λ = 2.16 m, then the length of the string is:

A standing wave on a string of length L = 3 m fixed at both ends is described by: y(x,t) = 0.01sin⁡(πx)cos⁡(40t), where x and y are in meters and t is in seconds. The maximum transverse speed of an element on the string located at x = 1/6 m is:

3. A target in a shooting board consists of a vertical square wooden board, 0.250 m on a side and with a mass 750 g and pivots around a horizontal axis along its top edge. The board is stuck faceon at its center by a bullet of mass 1.90 g, travelling at 360 m/s that remains embedded in the board.

(a) (2 marks) What is the angular speed of the board just after the bullet’s impact?

(b) (2 marks) What maximum height does the center of the board reach from the equilibrium before it starts swinging down again?

(c) (2 marks) What minimum bullet speed is needed for the board to swing all the way over after the impact?

A solid sphere of mass 2 kg and a massless string of total length 4 meters which is wrapped around the equator of the sphere (total length includes the length of wrapped string and the length of the string hanging from the ceiling). The sphere then falls vertically while rolling down (without slipping) the whole wrapped string and falls on top of an inclined plane. Due to the collision with the inclined plane, it loses all its kinetic energy within a very short time and starts rolling along the inclined plane with zero initial velocity. Consider that a total of 10 Joules of energy is lost during the motion of the sphere along the planes.The magnitude of gravitational acceleration g = 9.8 𝑚/𝑠2. (a) Find the value of the moment of inertia of the sphere about its axis of rotation.(b) What is the magnitude of angular velocity of the sphere when it touches the inclined plane?(c) How far along the second inclined plane (45º) on the right will the center of the sphere travel before it comes to a stop?

A pinball machine launch ramp consisting of a spring and a 30∘ ramp of length L.

(a) (3 marks) If the spring is compressed a distance 𝑥 from its equilibrium position and is then released at 𝑡 = 0, the pinball (a sphere of mass 𝑚 and radius 𝑟) reaches the top of the ramp at 𝑡 = 𝑇. Derive the expression for the spring constant 𝑘 in terms of 𝑚, 𝑔, 𝑥, and 𝐿.[Assume that the friction is sufficient, and the ball begins rolling without slipping immediately after launch.]

(b) (2 marks) What is the potential energy of the ball when it is at the midpoint of the ramp?

(c) (3 marks) Derive the expression of the speed of the ball immediately after being launched in terms of 𝑔 and 𝐿. 

How do I deduce the width of a refractive glass block

A cheering squad is made up of three members: Lynne of 50kg moving at 3 m/sNorth. Angie of mass 58kg moving eastward at 3 m/s and Mercy of mass 6 kg moving at 3 m/s south. What is the combined momentum of the squad?