## Physics Questions and Answers

Physics

### How much work does the electric field do in moving a proton from a point with a potential of +125 V to a point where...

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...

Physics

### At what distance from a long straight wire carrying a current of 5.0 Amps is the magnitude of the magnetic field due...

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...

Physics

### A +35 "mu"C point charge is placed 32 cm from an identical +35 "mu"C charge. What is the electric potential at the...

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...

Physics

### How much current is flowing in a wire 4.8 m long if the maximum force on it is 0.75 N when placed in a uniform 0.08 T...

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,...

Physics

### A 4357 kg roller coaster starts from rest at the top of a 36.5 m high track. Determine its speed of the car at the...

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...

Physics

### A football player runs 11m [N20E]. He then changes direction and then runs 9m [E]. What is his total displacement?

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...

Physics

### Consider two copper wires. One has twice the length of the other. How do the resistivities of these two wires compare?

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...

Physics

### A canoe has a velocity of 0.40m/s southeast relative to the earth. The canoe is on a river that is flowing 0.50m/s...

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...

Physics

### Light enters a substance from air at an angle of 32 degrees, and continues at an angle of 23 degrees. What is the...

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...

Physics

### If a material has an index of refraction of 2.25, what is the speed of light through it?

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...

Physics

### there is a special incident ray that reflects right back to itself how would you aim this incident ray to achieve...

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...

Physics

### 93 Million Miles To Meters

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)`...

Physics

### An optic fiber is made of clear plastic with index of refraction of 1.50. For what angles of incidence will light...

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...

Physics

### An electron acquires 7.45 x 10^-17 J of kinetic energy when it is accelerated by an electric field from plate A to...

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...

Physics

### If an electric wire is allowed to produce a magnetic field no larger than that of earth (5.5 x 10^-5 T) at a distance...

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...

Physics

### How much work does the electric field do in moving a -7.7 `muC` charge from ground to a point where potential is +55...

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...

Physics

### Three factors which determine the horizontal distance traveled: how does the velocity changes in each direction? An...

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...

Physics

### A parallel-plate capacitor consistsof plates of area 1.5 x 10^-4 m^2. And separated by 1.0 mm. The capacitor is...

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...

Physics

### A car with 62 cm diameter tires accelerates uniformly from rest to 20m/s in 10s. How many times does each tire...

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 =...

Physics

### How can I drop a raw egg 100 feet from the air without breaking it? The egg can't be boiled and we can use any thing...

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...

Physics

### Can you show how to calculate the magnitude of the magnetic force on a 160 meter length of straight wire stretched...

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...

Physics

### A lighted candle is 10 m away from a wall. A concave mirror is being used to project an image of the candle onto the...

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 =...

Physics

### why ray of light passes undeviated through optics centre of a lens?

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....

Physics

### Use Hooke's Law to determine the variable force in the spring problem. An overhead garage door has two springs, one...

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...

Physics

### Why is it so hard to get students to learn even simple physics? Why is it so hard to get students to learn even...

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...

Physics

### Light enters a substance from air at 45 degrees to the normal. It continues through the substance at 34.7 degrees to...

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...

Physics

### A car goes on a straight road 15 m/s, acceleration at a constant rate of speed of 21 m/s^2 in 12 seconds, what is the...

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 =...

Physics

### What Is 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,...

Physics

### A ball is thrown horizontally, its initial speed is 10 m/s. It hits the gound after 4 seconds. How far away did it...

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...

Physics

### A power station delivers 600 kW of power at 12,000 V to a factory. What current is required to deliver this power...

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...

Physics

### Question on point charge particles in a square Two pos. and two neg. point particles, all with charge of magnitude q...

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...

Physics

### A wire of length 55.5 cm carrying 8.75 Amps flows through a uniform magnetic field. The wire experiences a maximum...

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...

Physics

### Light is passing through a transparent material at an angle of 63 degrees. The material has an index of refraction...

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...

Physics

### Should I choose a career in Physics or Chemistry? I'm at the end of high school, and still undecided about my future...

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...

Physics

### A ball is thrown verticallyup at 10m/s.returns to ground with a velocity of 9m/s. What is the maximum height...

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...

Physics

### A garbage truck crashes head-on with a Volkswagen and the two come to rest in a cloud. Which experiences the greater...

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...

Physics

### An object is 2.3 cm tall, and 5.5 cm from a converging lens. The image is upright and 9.0 cm tall. What is the...

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...

Physics

### A marble is shot at an angle of 30 degrees and has an initial velocity of 40 m/s. How many seconds to reach the...

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...

Physics

### How do you find the answer, I know it's simple, but I'm missing it! A horizontal force is used to pull a 5.0 kg cart...

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...

Physics

### Can you describe the effect on friction force on the surface of Mars? How about the surface of Jupiter? (in regards...

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....

Physics

### If the net force of an object is 0, what is it most likely doing? a) it's at restb) it's acceleratingc) it's in...

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...

Physics

### What is the direction of the magnetic field lines of force due to current loop of circular shape? 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...

Physics

### How can I solve this question of Dynamics ??

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) =...

Physics

### What gas can be used to produce the following result? I want to achieve temperatures of between 30 deg C and 40...

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...

Physics

### A uniform electric field of 50 V/m is directed toward the east. If the voltage measured relative to ground at a...

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...

Physics

### A 75 nC charge is 8.0 m from a second charge, and the force between them is 1.0 N. What is the magnitude of the...

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...

Physics

### What happens to the energy of the system The oscillations of an actual spring-block system slowly reduce in amplitude...

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....

Physics

### An object is 2.3 cm tall, and 5.5 cm from a converging lens. The image is upright and 9.0 cm tall. What is the...

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...

Physics

### If the electricity delivered to a factory is at 50,000 Volts, What is the current use and the power dissipated in the...

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...

Physics

### If a person glides through the air at a height of 215 m with a velocity of 25.4 m/s, suddenly they dive to a height...

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...

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