A 4.2 kg lead ball is dropped into a 2.4 L insulated pail of water initially at 20.0∘C.

If the final temperature of the water-lead combination is 26.0 ∘C, what was the initial temperature of the lead ball?

What are the three most common types of radioactive decays? How do they differ? Also how many types of decays are there? Please describe them.

Chapter 2, #31

You are driving through town at 12 m/s when suddenly a car backs out of a driveway in front of you. You apply the brakes and begin decelerating at 3.3 m/s2. How much time does it take to stop? After braking half the time found in part A, is your speed 6.0 m/s, greater than 6.0 m/s, or less than 6.0 m/s?

1. 1. In polarizing microscopy, what is and what happens when a sample is anisotropic?

2. 2.What can happen to image of an anisotropic sample when you rotate it?

3.      3.What additional piece of equipment is added to a polarizing microscope to control anisotropic behavior? How does it accomplish control?

Devise a straightforward method that allows you to calculate (a) the speed and (b) the angular momentum of an electron in the nth Bohr orbit. Your expressions should contain the number of the orbit, n, and constants.

Using the formula that you devised, calculate the speed of an electron and the angular momentum of an electron in the tenth Bohr orbit. Units for answers are m/s for speed and J/s for angular momentum.

Free-body Diagrams - 01

Due in 21 hours, 49 minutes

A free-body diagram is a major tool we use to help analyze problems involving forces. To create a free-body diagram, place a dot on the paper to represent the object (or objects) of interest and then draw all of the forces acting on that body. The force vectors are drawn with their tail on the dot. A major step in any of our force problems is correctly identifying all of the forces acting on an object. There are three possible free-body diagrams shown at the top of the problem. Select the appropriate free-body diagram for each of the situations listed below. If there are two items mentioned, select the free-body diagram for the first object mentioned (book, block, you, ball).

A [One arrow pointing down]
B [One arrow pointing down, on down, one left, one right]
C [One arrow pointing down, one pointing up]

A

B

C
  A book is sitting stationary on a table.

A

B

C
  A block is being pulled by a string to the right at a constant speed. There is friction between the block and the table.

A

B

C
  You are standing stationary on a flat floor.

A

B

C
  A block is hanging from a string and is not accelerating.

A

B

C
  A ball is flying through the air. Ignore air resistance (assume projectile motion).

Incorrect. Tries 1/10 Previous Tries

Find the fundamental frequency and the frequency of the first three overtones of a pipe 55.0 cm long, if the pipe is open at both ends.

Please enter your answer as four numbers, separated with commas.

Find the fundamental frequency and the frequency of the first three overtones of a pipe 55.0 cm long, if the pipe is closed at one end.

Please enter your answer as four numbers, separated with commas.

If the pipe is open at both ends, what is the number of the highest harmonic that may be heard by a person who can hear frequencies from 20.0 Hz to 2.00×10⁴ Hz?

If the pipe is closed at one end, what is the number of the highest harmonic that may be heard by a person who can hear frequencies from 20.0 Hz to 2.00×10⁴ Hz

A sealed vertical cylinder of radius R and height h = 0.616 m is initially filled halfway with water, and the upper half is filled with air. The air is initially at standard atmospheric pressure, p0 = 1.01·105 Pa. A small valve at the bottom of the cylinder is opened, and water flows out of the cylinder until the reduced pressure of the air in the upper part of the cylinder prevents any further water from escaping. By what distance is the depth of the water lowered? (Assume that the temperature of water and air do not change and that no air leaks into the cylinder.)

Two stationary positive point charges, charge 1 of magnitude 4.00nC and charge 2 of magnitude 1.70nC , are separated by a distance of 39.0cm . An electron is released from rest at the point midway between the two charges, and it moves along the line connecting the two charges.

What is the speed vfinal of the electron when it is 10.0cm from charge 1?

A -11.0 nC point charge and a +22.0nC point charge are 18.0 cm apart on the x-axis.

A)What is the electric potential at the point on the x-axis where the electric field is zero?

B) What is the magnitude of the electric field at the point on the x-axis, between the charges, where the electric potential is zero?

Calculate the effective value of g, the acceleration of gravity, at 7400m above the Earth's surface.

Calculate the effective value of g, the acceleration of gravity, at 7400 km above the Earth's surface.

A person walks into a room that has, on opposite walls, two plane mirrors producing multiple images. Find the distances from the person to the first three images seen in the left-hand mirror, when the person is 5.60 ft from the mirror on the left wall and 13.9 ft from the mirror on the right wall.

A. First Image= 11.2ft

B. Second Image?

C. Third Image?

Consider the following thermodynamic properties:
(i) work done on a system; (ii) heat absorbed; (iii) entropy; (iv) enthalpy.
Which of these properties are state functions?

(a) (i) and (ii) only
(b) (i) and (iii) only
(c) (i) only
(d) (iii) and (iv) only

The figure below shows a bar of mass m = 0.280 kg that can slide without friction on a pair of rails separated by a distance ℓ = 1.20 m and located on an inclined plane that makes an angle θ = 29.5° with respect to the ground. The resistance of the resistor is R = 1.50 Ω, and a uniform magnetic field of magnitude B = 0.500 T is directed downward, perpendicular to the ground, over the entire region through which the bar moves. With what constant speed v does the bar slide along the rails?

A projectile is shot from the edge of a cliff h= 245 m above ground level with an initial speed of v0= 155 m/s at an angle of 37.0 with the horizontal, as shown in the Figure.

a. What are the horizontal and vertical components of the initial velocity?

b. Determine the time taken by the projectile to hit point P at ground level

c. Determine the range X of the projectile as measured from the base of the cliff

d. Find the maximum height above the cliff top reached by the projectile

e. What is its speed right before it hits the ground?

Please Explain!! how to solve each step.!