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1>What is the electric potential at a point 0.45 m away from a point charge of a of 2.5mC 2> If 3.75 X 10^-4 J of work are required to move 13.7 microc of charge from one point to another, what is the electric potentail difference the two points. 3> An electron is released from rest in a vacumm between two flat, parallel

Micro-F Capacitor Voltages

Hi. Can someone please check these two answers? (a) seems very low and (b) seems very high to me. A 0.22 micro-F capacitor is charged by a 1.5-V battery. After being charged, the capacitor is connected to a small electric motor. Assuming 100% efficiency, (a) to what height can the motor lift a 5.0-g mass? (b) What initial vol

Fluids, Pressure and Depth

A patient is to receive an intravenous injection of medication. In order to work properly, the pressure of fluid containing the medication must be 109 kPa at the injection point. (a) If the fluid has a density of 1020 kg/m^3, find the height at which the bag of fluid must be suspended above the patient. Assume that the pressure

Laws of Motion/Free Fall

Question: When baseball players throw the ball in from the outfield, they usually allow it to take one bounce before it reaches the infield, on the theory that the ball arrives sooner that way. Suppose that the angle at which a bounced ball leaves the ground is the same as the angle at which the outfielder threw it, but that the

Classical Physics Problems

1. During a rockslide, a 520 kg rock slides from rest down a hillside that is 500m long and 300m high. The coefficient of kinetic friction between the rock and the hill surface is 0.25 (a) If the gravitational potential energy U of the rock-Earth system is zero at the bottom of the hill, what is the value of U just before the

The Conservation of Energy

A skier coasts down a very smooth, 10-m-high slope (v =20 m/s), what is his speed at the bottom of the slope. If the skier has a mass of 60kg and the force of friction retards his motion by doing 2500 j of work, what is his speed at the bottom of the slope?

Spring constant problem: Work done, speed of block, maximum compression

A 230 g block is dropped onto a relaxed vertical spring that has a spring constant of k = 2.5 N/cm (Fig. 7-30). The block becomes attached to the spring and compresses the spring 14 cm before momentarily stopping. What work is done on the block by the spring force while the spring is being compressed? (in J) What is the s

Strength of a fishing line

1. The tension at which a fishing line snaps is commonly called the line's "strength." What minimum strength is needed for a line that is to stop a salmon of weight 85 N in 8.0 cm if the fish is initially drifting at 2.5 m/s? Assume a constant deceleration.

Two conducting wires each of length L are...

Two conducting wires each of length L are connected to a knob, whereby a total electric charge Q is deposited onto two small spherical metallic spheres, each of mass m and diameter d, at the end of the wires. We observe each wire of this electroscope to lie at an angle q from the vertical. Find an expression for the charge Q

Kinetic frictional force for a skier: Work done, magnitude of force

A 63 kg skier coasts up a snow-covered hill that makes an angle of 25 degrees with the horizontal. The initial speed of the skier is 6.6 m/s. After coasting a distance of 1.9 m up the slope, the speed of the skier is 4.4 m/s. (a) Find the work done by the kinetic frictional force that acts on the skis. (b) What is the magni

Power, work

A car can accelerate from rest to 25 m/sec in 12 seconds on a level road. The weight of the car is 10,000 newtons. Determine (a) power used in the acceleration in Kw. (b) Maximum speeed it will be able to maintain on an uphill road of angle 30 degrees. (c) Work done by the force during the first 5 seconds from start. (d) avera

Work/kinetic friction on a system moving at constant speed.

"A 276 kg piano slides 4.02 m down a 30.2° incline and is kept from accelerating by a man who is pushing back on it parallel to the incline, as seen in the figure (attached in a Word file). The effective coefficient of kinetic friction is 0.400. Calculate the work done by the man on the piano." See attached file for full pro

X-ray production

X-ray production: dependence of wavelength and intensity on various parameters. Tips to remember.

Calculate the Force of a Spring Function

On a frictionless table, one end of a spring is fixed. A cord attached to the free end pulls it along a meter scale beginning from 0. A record is made of the position of the free end, x, and the resisting force, F, exerted by the spring on the cord. SEE ATTACHMENT #1 for the parameters and a record of F vs x, showing position

Archimedes Principle: An object, part aluminum, part wood

See attached file. Two blocks are cemented together top to bottom and the whole object is placed in water. Known values are the density of the wood Dw= .650 kg/m^3, of aluminum Da = 2700 kg/m^3, and of water Dliq= 1000 kg/m^3. See attachment #1 for diagram, (not to scale). PART a. If the object barely floats, with the top

Working with elastic potential energy and a bowstring.

An archer pulls the bowstring back for a distance of 0.470 m before releasing the arrow. The bow and string act like a spring whose spring constant is 425 N/m. (a) What is the elastic potential energy of the drawn bow? (b) The arrow has a mass of 0.0300 kg. How fast is it traveling when it leaves the bow?

Moment of Inertia of a thin uniform rod by integration

A thin, uniform rod has length L and mass M. a. Find by integration its moment of inertia about an axis perpendicular to the rod at one end. b. Find by integration its moment of inertia about an axis perpencicular to the rod at its center of mass.

Working with spring oscillations and friction.

A block attached to a spring is acted on by a spring with spring constant k and a weak frictional force of constant magnitude f. The block is pulled a distance Xo from the equilibrium and released. It oscillates many times and eventually comes to rest. a) Show that the decrease of amplitude is the same for each cycle of osci

Electricity Problem

A +30e-6 charge is placed 32 cm form an idnetical +30e-6 charge. How much work would be required to move a +50e-6 test charge from a point midway between them to a point closer to either of the charges?

Problem relating to centroid

The asking problem: For the semiannular area, determine the ratio of r1 to r2 for which the centroid of the area is located at x=-1/2*r2 and y=0. Note: This problem is a 2D problem and not a 3D. It was taken from the «Distributed forces: Centroids and Centers of Gravity» section of my static course. The files is in word97

Determining the elongation in a spring when the mass is immersed in water.

A copper piece of mass 10g is suspended by a vertical spring. The spring elongates 1cm over its natural length to keep the piece in equilibrium. A beaker containing water is now placed below the piece so as to immerse it completely in water. Find the elongation of the string. Density of copper is 9000 kg/m^3 g = 10 m/s^2

Electomagnetic Induction

1. Imagine a superconductor in its normal state in the shape of a ring immersed in a magnetic field parallel to the central axis (that is, perpendicular to the plane of the ring.) Suppose the ring is cooled and becomes superconducting. (a) Describe what happens to the field (b) If the ring is pulled parpendicularly out of the