A 34.8-kg child starting from rest slides down a water slide with a vertical height of 16.0 m. (Neglect friction.)

(a) What is the child's speed halfway down the slide's vertical distance?

m/s

(b) What is the child's speed three-fourths of the way down?

m/s

Gauss's Law

A spherical shell of radius R has charge Q spread uniformly over its surface.
Find the electric field inside and outside the shell.

Imagine that you have just purchased a coffee in a cup, with a lid. You place your coffee cup on a table and it starts to cool down. We are going to model this cooling process. Choose whatever type of coffee cup you are most familiar with.

2. Do a Ninja Physics estimate of how long it will take for the sides of the cup to warm up.

The specific heat capacity of water (and coffee) is around 4200 J Kg-1 K-1. Cardboard has a thermal conductivity of around k ~ 0.025 W m-2 K-1 , a density of around 700 kg m-3 and a specific heat capacity of around 1400 J kg-1 K-1. Glass has a thermal conductivity of around k ~ 1 W m-2 K-1, a density of around 2500 kg m-3 and a specific heat capacity of around 700 J kg-1 K-1. Styrofoam (foamed plastic) has a thermal conductivity similar to air and a density of around 50 kg m-3, while hard plastics have thermal conductivities of k ~ 0.025 W m-2 K-1 and densities similar to water: both have specific heat capacities of around 1500 J Kg-1 K-1.

A 420-N uniform rectangular sign 4.00 m wide and 3.00 m high is suspended from a horizontal, 6.00-m-long, uniform, 130-N rod as indicated in the figure below. The left end of the rod is supported by a hinge and the right end is supported by a thin cable making a 30.0

A thin spool with a mass of 2.0kg and a radius of 15cm is hung in a fixed position so that it is free to rotate. A massless string is wrapped around it with a 0.80kg mass tied at the end. When the mass is released, the spool begins to unwind.

What is the rotational inertia of the spool? (You can treat it as a thin disk.)

What is the kinetic energy and angular momentum of the spool 2.0s after the

hanging mass is released?

What is the kinetic energy and angular momentum of the spool after 3 full

rotations?

An object is placed 10 m before a convex lens with focal length 5 . 9 m . Another convex ens is placed 9 . 39 m behind the first lens with a focal length 3 . 8 m (see the figure below). Note: Make a ray diagram sketch in order to check your numerical answer a)At what distance is the first image from the first lens? Answer in units of m
b)What is the magnification of the first image?
c)At what distance is the second image from the second lens? Answer in units of m
d)What is the magnification of the final image, when compared to the initial object?

2(a) A typical metallic particle has a rest mass (i.e. mass when the particle is not moving) of 0.5x10-24Kg and an energy of 10 eV (Electron Volt). (i) What would be the wavelength and momentum of the associated wave for this particle? -- (5) (ii) Assuming the uncertainty principle and a spherical particle, estimate the diameter of this particle? Is it a nanoparticle ? ----------------------------------------- (5) (iii) This particle passes through an inter-lattice spacing of 1nm along the x axis. What would be the spread of the particle in the y-axis, 10microns from this interlattice spacing ------- (5) 2. (b) The primitive translation vectors of the hexagonal space lattice may be taken as z ccy a xaby a xaa     ; ) 2 () 4 3 (;) 2 () 4 3 ( (a) Calculate the volume of the primitive unit cell ------ (5) (b) What is its atomic packing fraction ? ----- (5)

A child is playing with a ball at the base of a hill. She rolls the ball up the hill with a speed of 8 m/s. After 23s, the ball comes back to her and has the same speed as when she rolled it but it's moving in the opposite direction. Assume that the ball's acceleration was constant as it rolled up and down the hill, and take the positive direction to point up the hill.

What was the ball's acceleration while rolling up and down the hill?

A swimming pool is 1.4 m deep and 12 m long. Is it possible for you to dive to the very bottom of the pool so people standing on the deck at the end of the pool do not see you?

A) Assume you dive to the very bottom of the pool so people standing on the deck at the end of the pool can see you. Find the minimum height of the person's eyes at the far side of the pool, so you would be observable by this person. Take an angle 48.5∘ for a ray that is incident at the water-air interface (nwater = 1.33).

B) Therefore, is it possible for you to dive to the very bottom of the pool so people standing on the deck at the end of the pool do not see you?

A loudspeaker of mass 17.0kg is suspended a distance of h = 2.40m below the ceiling by two cables that make equal angles with the ceiling. Each cable has a length of l = 2.50m .

What is the tension T in each of the cables?

Use 9.80m/s2 for the magnitude of the acceleration due to gravity.

A vase falls off a table and shatters into three fragments which move away horizontally across the floor. Fragment 1 has half the mass of the original vase and travels with speed 34.5 cm/s. Fragment 2 has one-quarter the mass of the original vase and travels with speed 26.6 cm/s in a direction perpendicular to Fragment 1.

What is the speed (in cm/s) of the third fragment?

Explain why there might be discrepancies for the different types of radiation if graphed in the same manner as your count rate versusinverse square of the distance graph. What type of radiation would you imagine having the most discrepancy?

Two frictionless “hoverpucks” (puck 1 and puck 2) with mass 0.20 kg are travelling on a collision course with a third hoverpuck which is at rest and has mass 0.40 kg. Before they collide, puck 1 has velocity (1.0 m/s) î – (1.0 m/s) ĵ. After the collision they all stick together and have velocity (2.0 m/s) î + (0.5 m/s) ĵ. Friction is negligible.

a) What is the velocity of puck 2 before the collision?

b) What is the total impulse on puck 1 during the collision?

c) If the duration of the collision was 0.15 s what was the average force exerted by puck 3 on puck 1?

d) How much kinetic energy is gained or lost by the three-puck system?

A block of mass m = 2.00 kg is released from rest at h = 0.400 m above the surface of a table, at the top of a ? = 40.0

Always when we want to represent the magnetic field of the earth we see a similar image:

enter image description here

My question is, what exactly does this show? What are the blue and orange lines, what do they represent? Why are they curved like that? I have a vague idea about field lines, but I do not fully comprehend this. An explanation would be appreciated