Thursday

April 24, 2014

April 24, 2014

Total # Posts: 22

**physics**

The charged plates of a parallel plate capacitor each have a charge density of sigma C/m^2. Using Gauss's law, compute the electric field between the plates.

**physics**

A graphite rod is 1.0 m long, with a 1.0 cm by 0.5 cm rectangular cross sectional area. What is the electrical resistance between its long ends? What must be the diameter of a circular 2.0 m long copper rod if its resistance is to be the same?

**Physics**

8. In an ultracentrifuge a solution is rotated with an angular speed of 3000 rev/sec at a radius of 10 cm. How large is the centripetal acceleration of each particle in the solution? Compare the centripetal force needed to hold a particle of mass 10-5 gm with the weight of the...

**physics**

A torque of 0.97 N-m is applied to a bicycle wheel of radius 0.35 m and mass 0.75 kg. Treating the wheel as a hoop, find its angular acceleration.

**physics**

The moment of inertia of a 0.98 kg bicycle wheel rotating about its center is 0.13 km-m^2. What is the radius of the wheel? Ignore the mass of the wheel's spokes.

**physics**

The collision between a nail and hammer can be considered to be approximately elastic. Calculate the kinetic energy acquired by a 12gm nail when it is struck by a 550 gm hammer moving with an initial speed of 4.5 m/sec.

**physics**

A street ball bearing of radius 0.50 cm is rolling along a table at 20cm/sec when it starts to roll up an incline. How high above the table level will it rise before stopping? Ignore friction losses.

**physics**

find the rotational kinetic energy of the earth about the sun due to its orbital about the sun. The mass of the each M is 6 X 10^24 kg, the orbital radius r is 1.5 X 10^11 m and the rotational period T is 1 year. Hint, treat the earth as a point mass in this problem.

**physics**

A solid ball of radius b and mass m is released from the top of an incline of the incline is at the height h above the ground. If the ball rolls without slipping, what willl be its linear speed when it reaches the botton of the incline?

**physics**

A ball of mass moves in a horizontal circular path of radius a with speed v as shown in the illustration below. Find the tension in the cord.

**physics**

A ball of mass m is rotated at constant speed v in a vertical circle of radius r as shown below. Find the tension in the cord when the ball is at position A and position B. (Position a is in top of the wheel, position B is on the bottom of the wheel, 180 degrees apart.)

**Physics**

A wheel with 50 cm diameter is moving at a speed of 20 m/sec. (a) How fast is the wheel turning? (b) How many revolutions will the wheel turn if it coasts uniformly to rest in 30 sec?

**physics**

A wheel is turning at a speed of 2.0 rev/sec and is allowed to coast to rest. If it does so in 30 sec, how far did it turn in the process? Assume uniform acceleration.

**physics**

(a)Calculate the work done by moving a 50 kg mass along each of the legs of the path shown below. What is the total work expended when going along the entire path? Show all work. Don't just state any obvious results, if any. AB= 5m BC= 10m CD= 19.14m DA= 10m Angle between ...

**physics**

A piano of mass 800 kg is hoisted up to a 15 meter height. Just then, the rope breaks with the piano plummeting down to the ground. What is the velocity of the piano when it strikes the ground?

**physics**

A 60 kg skydiver moving at terminal speed falls 50 m in 1 sec. What power is the skydiver expending on the air? The terminal speed of the falling object is the maximum constant speed the object will reach due to the opposing force of air resistance.

**physics**

A man whose mass is 70 kg walks up to the third floor of a building. This is a vertical height of 12 m above the street level. (a) How many joules of work has he done? (b) By how much has he increased his potential energy? (c) If he climbs the stairs in 20 sec, what was his ra...

**physics**

A 2 kg block is pushed 2 m along a fixed horizontal surface by a horizontal force of 20 N. The coefficient of kinetic friction of the surface is µk= 0.40. (a) How much work is done by the 20 N force? (b) what is the work done by the friction force? (c) What is the total ...

**physics**

Your electricity usage for a one month period is 500 kilowatt-hours. Assuming one month is equal to 30 days and that the electricity usage is uniform across the whole month, what would be the velocity of a 1 kg mass if it was given the kinetic energy equivalent to one day'...

**physics**

A 2kg block is placed onto a vertically oriented spring whose spring constant k is 1960 N/m. Find the distance that the spring will be compressed.

**physics**

A body slides down a curved track which is one quadrant of a circle of radius R. If it starts from rest at the top of the track and there is no friction, find the speed at the bottom of the track is R equals 5 m.

**physics**

The scale of a certain spring balance reads 1200 N when the spring is stretched 0.1m. (a) What is the potential energy of the spring when it is stretched 0.1m and when it is stretched 0.5 m? (b) What is the potential energy when a 50 kg mass hangs from the spring?

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