An air bubble of 21 cm3 volume is at the bottom of a lake 32 m deep where the temperature is 4.0°C. The bubble rises to the surface, which is at a temperature of 24°C. Take the temperature of the bubble's air to be the same as that of the surrounding water. Just as the bubble reaches the surface, what is its volume?

Write a reflection on Maxwell's Equations and how they relate to each other and physics as well as what they do. Give a break down to the equations as well as to how they relate to natural phenonmena

1) A wheel with a weight of 396 N comes off a moving truck and rolls without slipping along a highway. At the bottom of a hill it is rotating at an angular velocity of 27.5 rad/s . The radius of the wheel is 0.584 m and its moment of inertia about its rotation axis is 0.800 MR2. Friction does work on the wheel as it rolls up the hill to a stop, at a height of h above the bottom of the hill; this work has a magnitude of 3550 J .

Calculate h.

Use 9.81 m/s2 for the acceleration due to gravity.

2) A hollow spherical shell with mass 2.45 kg rolls without slipping down a slope that makes an angle of 38.0 ∘ with the horizontal.

Part A

Find the magnitude of the acceleration acm of the center of mass of the spherical shell.

Take the free-fall acceleration to be g = 9.80 m/s2 .

Part B

Find the magnitude of the frictional force acting on the spherical shell.

Take the free-fall acceleration to be g = 9.80 m/s2 .

The basic cosmological argument assumes that an infinite regress of cause and effect is unsatisfactory because it does not explain why something exists instead of nothing. True or false

1. The Lifetime of the Sun. The total mass of the sun is about 2 x 10³⁰ kg, of which about 75% was hydrogen when the sun formed. However, only about 13% of this hydrogen ever becomes available for fusion in the core. The rest remains in layers of the sun where the temperature is too low for fusion.

       a) Use the given data to calculate the total mass of hydrogen available for fusion over the lifetime of the sun.

       b) The sun fuses about 600 billion kilograms of hydrogen each second. Based on your results from part (a), calculate how long the sun’s initial supply of hydrogen can last (in seconds, and in years); that is, calculate the expected lifetime of the sun.

       c) Given that our solar system is now about 4.6 billion years old, when will we need to worry about the sun running out of hydrogen?

QUESTION 4

a) Define speed, velocity and acceleration stating whether they are scalar or vector quantities. Support with calculative examples ( 9 marks)

b ) Draw a graph of an object that starts from rest and accelerates at 4m/s^2 until for 5 seconds, then travels at a constant velocity for 3 seconds and then decelerates at 8 m/s^2 until it comes to rest. Determine; ( 16 marks)

the constant velocity;

the displacement during acceleration

the displacement of constant velocity

the time taken for deceleration and

the displacement during deceleration

What is the difference between the magnetic field of the bar magnet and

the magnetic field of the solenoid? (also in terms of how the lines and direction should differ)

Jack (mass 55.0 kg) is sliding due east with speed 8.00 m/s on the surface of a frozen pond. He collides with Jill (mass 44.0 kg), who is initially at rest. After the collision, Jack is traveling at 5.00m/s in a direction 34.0∘ north of east. Ignore friction.

a) What is the direction of the Jill's velocity after the collision? Express your answer in degrees.

b)What is the magnitude of the Jill's velocity after the collision? Express your answer with the appropriate units.

Solve the wave equation using The Laplace Transformation . ( in detail please )

Boxing gloves are padded to lessen the force of a blow.

(a) Calculate the force exerted by a boxing glove on an opponent's face, if the glove and face compress 7.00 cm during a blow in which the 8.00 kg arm and glove are brought to rest from an initial speed of 10.0 m/s.
N
(b) Calculate the force exerted by an identical blow in the gory old days when no gloves were used and the knuckles and face would compress only 2.00 cm. (Assume the total mass of the arm remains 8.00 kg.)
N
(c) Discuss the magnitude of the force with glove on. Does it seem high enough to cause damage even though it is lower than the force with no glove?

In a downhill ski race surprisingly little advantage is gained by getting a running start. This is because the initial kinetic energy is small compared with the gain in gravitational potential energy even on small hills. To demonstrate this, find the final speed and the time taken for a skier who skies 70.0 m along a 25° slope neglecting friction for the following two cases. (Note that this time difference can be very significant in competitive events so it is still worthwhile to get a running start.)

(a) starting from rest
final speed
m/s
time taken
s

(b) starting with an initial speed of 3.00 m/s
final speed
m/s
time taken
s

(a) How high a hill can a car coast up (engine disengaged) if friction is negligible and its initial speed is 76.0 km/h?
m
(b) If, in actuality, a 750 kg car with an initial speed of 76.0 km/h is observed to coast up a hill to a height 11.0 m above its starting point, how much thermal energy was generated by friction?
J
(c) What is the average force of friction if the hill has a slope 2.5° above the horizontal? (Explicitly show on paper how you follow the steps in the Problem-Solving Strategy for energy found on pages 159 and 160. Your instructor may ask you to turn in this work.)
N (down the slope)

When a golf ball or basketball is dropped to the pavement, it bounces backup. (i) Is a force needed to make it bounce back up? (ii) if so, what exerts the force?

(b) Whiplash sometimes results from an automobile accident when the victim

Explain your interpretation and understanding of The Doppler Effect.

Along with that I also would like you all to discuss the interesting facts about light

A number 14 copper wire has a diameter of 1.628 mm. Calculate the resistance of a 34.0 m long piece of such wire.
(Use 1.72×10^-8 Ωm for the resistivity of copper.)

2.809×10^-1 Ohm
For safety, the National Electrical Code limits the allowable amount of current which such a wire may carry. When used in indoor wiring, the limit is 15.0 A for rubber insulated wire of that size. How much power would be dissipated in the wire of the above problem when carrying the maximum allowable current?

6.321×10¹ W

What would be the voltage between the ends of the wire in the above problem?

4.214 V

What is the current density in the wire when it is carrying the maximum allowable current? (Current density is the current in the wire divided by the cross sectional area of the wire.)

NEED HELP
What is the drift velocity of the electrons when the wire is carrying the maximum allowable current?
(The density of electrons in copper is 8.47×10²⁸ m^-3.)

NEED help

A cylinder radius R is rolling down a slope, angle ø. There is sufficient friction that the cylinder rolls without slipping, but do not assume the friction is maximum static friction. Known quantities are R, g, ø

What is the linear acceleration of the cylinder down the slope?