# Physics

## Physics Questions and Answers

Physics

Given: V_a = +125 V V_b = -55.0 V and q_p = +1e = +1.602\times10^-19\text(C) The electric field does work on the proton much like the gravitational field does work on a mass. A mass falls from high...

Latest answer posted April 23, 2013 1:42 am UTC

1 educator answer

Physics

The magnetic field due to a current flowing through an infinitely long wire is given by B = (mu*I)/(2*pi*r) where B is the magnetic field, mu is the permeability of free space and equal to...

Latest answer posted April 10, 2013 3:23 am UTC

1 educator answer

Physics

If the two charges are 32 cm from each other, than the distance of the mid point to each charge is r = 32/2 = 16 cm. The equation for voltage (V) with respect to charge (Q) is V=(kQ)/r , where k...

Latest answer posted May 13, 2013 6:11 pm UTC

1 educator answer

Physics

If a wire of length L carrying a current I lies in a magnetic field B, the force on the wire due to the interaction between magnetic fields is given by F = I*LxxB . For a wire that is 4.8 m long,...

Latest answer posted April 10, 2013 4:03 am UTC

1 educator answer

Physics

The roller coaster with mass 4357 kg is initially at rest at a height 36.5 m. It moves down and reaches the top of a loop where its height is 10.8 m. To determine the speed of the roller coaster at...

Latest answer posted January 30, 2013 8:10 am UTC

1 educator answer

Physics

The football player runs 11m in a direction N20E. He then changes direction and then runs 9m towards the east. To find the displacement of the player, divide the initial 11m run in the direction...

Latest answer posted April 10, 2013 4:39 am UTC

1 educator answer

Physics

The resistivity of a material using which a resistor is made is constant. It does not depend on the dimensions of the resistor though it may vary with other factors like temperature. If two copper...

Latest answer posted April 3, 2013 3:46 am UTC

1 educator answer

Physics

This is vector problem, but you can also think of this in small chunks For every 0.4m to the south east, the boat gets pushed east 0.5 m. We determine where the boat is after 1 second, find the...

Latest answer posted April 21, 2013 5:20 pm UTC

1 educator answer

Physics

Answer: 47.5° This is similar to another post. You can review the concept there - the link is in the reference. Snell's Law and the Critical angle formula combine... Make sure to keep track of...

Latest answer posted April 25, 2013 1:37 am UTC

1 educator answer

Physics

To solve, apply the formula of index of refraction which is:n=c/v where,n - index of refractionc - velocity of light in a vacuum ( 3 x 10^8 m/s) andv - velocity of light in a mediumSo, plug-in...

Latest answer posted April 25, 2013 12:30 am UTC

1 educator answer

Physics

When light rays reflect, the angle of incidence (the angle from which the ray is different from the normal of the surface, or the imaginary line coming straight out of the surface) is equal to the...

Latest answer posted May 12, 2012 3:43 am UTC

1 educator answer

Physics

This uses unit-analysis, a skillset of dimensional analysis. 93000000 miles -> ? m Convert to scientific notation 9.3\times10^7 mi It is known that 10^-2 m = 1 cm 2.54cm = 1 \text(in)...

Latest answer posted April 21, 2013 6:46 pm UTC

1 educator answer

Physics

When a beam of light passes from one medium to another the beam bends if the two mediums do not have the same refractive index. If the angle of incidence is A and the angle of refraction is B, the...

Latest answer posted May 19, 2013 6:02 am UTC

1 educator answer

Physics

Given \DeltaKE = 7.45\times10^(-17)\text(J) q_e = -1.602\times10^(-19)\text(C)  Due to the conservation of energy, the change in kinetic energy came from the change in potential energy due to...

Latest answer posted April 23, 2013 1:30 am UTC

1 educator answer

Physics

The magnetic field due to a current flowing through an infinitely long wire is given by B = (mu*I)/(2*pi*r) where B is the magnetic field, mu is the permeability of free space and equal to...

Latest answer posted April 10, 2013 3:30 am UTC

2 educator answers

Physics

The potential difference between the two points, or voltage Delta V,is defined as the work it would take to move a positive unit charge from the first point to the second, AGAINST the electric...

Latest answer posted April 22, 2013 8:25 pm UTC

1 educator answer

Physics

In typical simplified projectile motion, there are two axes of movement: vertical (y-axis) and horizontal (x-axis). The object flying through the air is in free-fall, meaning the net force acting...

Latest answer posted April 21, 2013 9:37 pm UTC

1 educator answer

Physics

The capacitance of a parallel plate capacitance is given by C = (k*epsi_o*A)/d where epsi_o is the permittivity of free space and equal to 8.854*10^-12 F/m, k is the relative permittivity of...

Latest answer posted April 30, 2013 7:01 am UTC

1 educator answer

Physics

Using laws of linear motion; v = u+at 20 = 0+a*10 a = 2 m/s^2 For angular and linear motion; a = ralpha alpha = a/r alpha = 2/((62/100)/2) = 200/31rad/s^2 From angular motion; theta =...

Latest answer posted November 29, 2012 1:22 am UTC

1 educator answer

Physics

There are a number of ways, we can solve this "egg-problem". A fall of 100 feet in the air is desired, without breaking the egg. Note that it is never the fall that breaks the egg, it is the impact...

Latest answer posted March 27, 2016 12:21 pm UTC

1 educator answer

Physics

If a wire of length L carrying a current I lies in a magnetic field B, the force on the wire due to the interaction between magnetic fields is given by F = I*LxxB . A straight wire of length 160...

Latest answer posted April 10, 2013 4:14 am UTC

1 educator answer

Physics

We can use the magnification equation to help us out: Magnification = the distance between the mirror and the image, divided by the distance between the object and the mirror. In other words: M =...

Latest answer posted June 5, 2016 5:06 am UTC

1 educator answer

Physics

Actually, in real lenses, the ray going through the center of the lens does NOT go straight through. It refracts like every other light ray. On entering the lens from air, the light ray is bent....

Latest answer posted April 21, 2013 6:24 pm UTC

1 educator answer

Physics

As the problem stated, we first need to figure out the spring constant. Hooke's Law says that the spring constant can be calculated by dividing the force by the distance of movement. It takes 15...

Latest answer posted November 11, 2016 6:36 pm UTC

1 educator answer

Physics

I have to agree with many of the above posters that the issue for physics in particular is the math. While motivation for any subject at any level is an issue for all educators, I think the...

Latest answer posted June 1, 2012 9:02 am UTC

7 educator answers

Physics

Answer: 53.6° Recall Snell's Law: n_1sin(\theta_1)=n_2sin(\theta_2) where n is the index of refraction of the material and \theta is the angle the ray makes with the normal (perpendicular) of...

Latest answer posted April 25, 2013 1:27 am UTC

1 educator answer

Physics

Here we have to use the velocity equations. S = Ut+1/2*a*t^2 If we put this equation from the time that starts acceleration to end of 12 seconds, S = distance travelled U = 15m/s a = 21m/s^2 t =...

Latest answer posted September 16, 2012 2:44 pm UTC

1 educator answer

Physics

Physics is the study of matter and energy. Since matter and energy are the two things that the entire universe is made of, physics is really the foundation of all the sciences. For convenience,...

Latest answer posted April 20, 2012 1:10 pm UTC

2 educator answers

Physics

The ball is thrown horizontally with an initial speed of 10 m/s and it hits the ground after 4 seconds. When the ball is released it moves in the downward direction due to the gravitational...

Latest answer posted November 14, 2012 4:59 pm UTC

1 educator answer

Physics

The power station delivers 600 kW of power at 12000 V to a factory. Power (P) is related to current (I) and voltage (V) by: P = V*I. Substituting the values in the problem 600000 = 12000*I => I...

Latest answer posted April 3, 2013 4:38 am UTC

1 educator answer

Physics

Since we are dealing with a test charge at the center of a square of side 0.1 m, the field from each corner will be directed along a diagonal of the square, toward the negative charges and away...

Latest answer posted April 21, 2013 5:06 pm UTC

1 educator answer

Physics

If a wire of length L carrying a current I lies in a magnetic field B, the force on the wire due to the interaction between magnetic fields is given by F = I*LxxB . In the problem, the wire of...

Latest answer posted April 10, 2013 3:54 am UTC

1 educator answer

Physics

When a beam of light passes from one medium to another the beam bends if the two mediums do not have the same refractive index. If the angle of incidence is A and the angle of refraction is B, the...

Latest answer posted May 19, 2013 5:56 am UTC

2 educator answers

Physics

Like #5 I think you should wait a bit before making a career choice. College is the best place to decide on a career. You can take courses in both physics and chemistry and see (1) how you like...

Latest answer posted July 29, 2012 2:44 am UTC

5 educator answers

Physics

For the motion of the ball we can apply equations of motion. Initial velocity (U) = 10m/s Final velocity at top (V) = 0m/s Acceleration due to gravity (g) = 10m/s Since the ball stops at maximum...

Latest answer posted January 12, 2013 3:30 am UTC

1 educator answer

Physics

The impact force they both experience is exactly the same. This is according to the third Newton's Law: in every interaction between two objects, the objects act on each other with the forces that...

Latest answer posted June 14, 2013 12:59 am UTC

1 educator answer

Physics

The magnification M is the ratio of image height to the object height: M=h_i/h_o=9/2.3=3.91 This ratio is equal to the ratio of the image distance to the object distance, from the similarity of...

Latest answer posted April 28, 2013 1:53 am UTC

1 educator answer

Physics

The marble is shot at an angle of 30 degrees to the horizontal and has an initial velocity of 40 m/s. The initial velocity of the marble can be divided into 2 components. The horizontal component...

Latest answer posted November 14, 2012 5:11 pm UTC

1 educator answer

Physics

Here what we need to recognise is the first law of Newton. His first law of motion says that an object will be at rest or travelling in constant velocity until an external force applied on it. so...

Latest answer posted February 1, 2013 10:09 am UTC

1 educator answer

Physics

If a refrigerator or a cabinet is placed on a surface its movement is resisted by the force of friction which is given by F = mu*N where mu is the coefficient of friction and N is the normal force....

Latest answer posted December 2, 2012 5:50 am UTC

1 educator answer

Physics

Here we have to memorize the Newtons laws of motion. In his first law of motion of an object he has stated that If the net force acting on a body is zero then the body is at rest or moving in a...

Latest answer posted January 12, 2013 3:45 am UTC

1 educator answer

Physics

While the right hand rule for a straight wire is the one described by another educator, the right hand rule for a LOOP of wire is similar, but notably different. With your right hand, make a...

Latest answer posted May 16, 2013 1:17 am UTC

1 educator answer

Physics

First, we need to find the resultant force acting on the block with the following equation: F = F1(hori) + F2(hori) – μN Where: F1(hori) = F1 cos 20°, is the horizontal component of F1 F2(hori) =...

Latest answer posted February 14, 2016 9:52 pm UTC

1 educator answer

Physics

Looking at the details provided in the question, your objective is to create a heating system that is non polluting and requires no external energy source. The temperature of the room being heated...

Latest answer posted January 19, 2016 5:13 am UTC

1 educator answer

Physics

The electric field lines always point in the directon of decreasing potential. So if the field points EAST, and the point in question is located to the WEST of the point with the voltage 80V, the...

Latest answer posted April 30, 2013 2:27 pm UTC

1 educator answer

Physics

Coloumb's law tells us that the electrostatic force of attraction between point charges is directly proportional to the product of the charges and inversely proportional to the square of the...

Latest answer posted May 13, 2013 5:01 pm UTC

1 educator answer

Physics

The energy used producing oscillations is kinetic energy. Total energy of the system is kinetic energy plus potential energy. Potential energy is energy not triggered for any action at any moment....

Latest answer posted November 26, 2012 4:50 pm UTC

1 educator answer

Physics

The object is 2.3 cm tall, and 5.5 cm from a converging lens. The image is upright and 9.0 cm tall. The magnification due to the lens is M = -9/2.3 . In terms of the distance of the object from...

Latest answer posted May 19, 2013 6:15 am UTC

1 educator answer

Physics

The voltage at which power is delivered to the factory is 12000V. To determine the current that travels through the wire that carry the power, either the power delivered or the resistance of the...

Latest answer posted April 3, 2013 4:58 am UTC

1 educator answer

Physics

The person is gliding at a height 215 m with a velocity 25.4 m/s. The sum of the kinetic energy and gravitational potential energy of the person is equal to (1/2)*m*v^2 + m*g*h where v is the...

Latest answer posted January 30, 2013 7:21 am UTC

1 educator answer

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