Physics Questions and Answers

Physics

Impulse is the change in momentum of an object. There are two impulses that your egg design will have to deal with. The first impulse is from the drop itself. Its momentum will increase due to the...

Latest answer posted April 21, 2013 5:52 pm UTC

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Physics

In order to find the answer to this question, you need to know the following equation: m = dv Where m is mass, d is density, and v is volume. In this case, you are looking for mass, you have...

Latest answer posted December 20, 2009 1:19 am UTC

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Physics

In a house, there are many electrical appliances that have to run independent of each other. If one appliance is turned on or off it should not affect the other appliances. This is not possible if...

Latest answer posted February 29, 2012 2:01 am UTC

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Physics

Yusef pushes the chair of mass 45 kg across a carpeted floor with a force of magnitude 144 N directed 35.0 degrees below the horizontal. The magnitude of the frictional force between the carpet...

Latest answer posted February 27, 2012 1:24 am UTC

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Physics

When the basketball is thrown up an initial velocity is imparted to it. This gives the ball a kinetic energy equal to (1/2)*m*v^2 where m is the mass of the ball and v is the velocity with which it...

Latest answer posted December 2, 2012 9:34 am UTC

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Physics

For a potential difference V across a resistor R, the current I that flows through the resistor is given by Ohm's law as I = V/R As current is inversely proportional to resistance, for the same...

Latest answer posted February 29, 2012 1:47 am UTC

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Physics

The law of conservation of energy states that the total energy in an isolated system does not change. It may change form, for example mechanical energy may get converted to thermal energy,...

Latest answer posted November 19, 2011 12:10 pm UTC

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Physics

The kinetic energy of an object with mass m and which has a speed of v is given by (1/2)*m*v^2. The change in the kinetic energy of the object as the speed changes is proportional to the square of...

Latest answer posted March 26, 2012 1:29 pm UTC

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Physics

Rearranging terms, E ( 4(3.1416)d^2 ) = P, so E ( 4(3.1416)[.9m^2] ) = 1200 lm E ( 12.57 [.81m^2] ) = 1200 lm E (10.17m^2) = 1200 lm E = 1200 lm / 10.17 m^2 E = 118 lm/m^2

Latest answer posted June 11, 2011 1:30 am UTC

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Physics

We have the position vector given in terms of time t. r(t) = t^3*i + t^2*j To find the velocity vector we have to differentiate r(t) with respect to time. r'(t) = 3t^2*i + 2t*j The vector...

Latest answer posted March 22, 2011 3:25 am UTC

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Physics

The resistance of a resistor is given by the formula `R = rho*l/A ` where `rho` is the resistivity of the material the resistor is made of, l is the length of the resistor and A is the...

Latest answer posted April 3, 2013 3:09 am UTC

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Physics

The formula for pressure is P = F/A In this equation, P stands for pressure while F stands for force and A stands for area. Pressure is typically measured in a unit called the Pascal. So what this...

Latest answer posted December 24, 2009 2:12 pm UTC

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Physics

The safe answer is C. See below why it could also be D: The best way to think of weight is this: weight is the measurement of resistance of a given mass to falling. On the earth, everything that...

Latest answer posted December 12, 2009 12:10 pm UTC

2 educator answers

Physics

Yes, an object can have both of these at the same time. Potential energy is energy that is stored in an object. Kinetic energy is the energy that is associated with motion. So what you have to...

Latest answer posted November 23, 2009 11:53 am UTC

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Physics

They both hit the ground at the same time. So your answer is C. Gravity works on the bullets just the same regardless of velocity. The bullets have to be the same calibre and weight for this to...

Latest answer posted June 1, 2009 8:55 am UTC

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Physics

At a height h, the gravitational potential energy P of an object with mass m is given by the relation P = m*g*h. If the object is considered to be a closed system, it is assumed that there is no...

Latest answer posted November 21, 2011 9:27 am UTC

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Physics

The gravitational potential energy of a body placed at a height h is given by PE = m*g*h where m is the mass of the body and g is the acceleration due to gravity. The mass of the rock is 21.1 kg...

Latest answer posted February 29, 2012 12:35 pm UTC

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Physics

The electrical conductivity of a metal has the SI units Siemens/meter. This is a reciprocal of the resistivity that is expressed in terms of ohm*m. Electrical conductivity of a metal is not the...

Latest answer posted November 4, 2011 1:41 pm UTC

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Physics

A body in motion has kinetic energy. Kinetic energy can be due to linear motion as well as angular motion. We don't need the acceleration due to gravity to determine the kinetic energy of the car....

Latest answer posted September 30, 2011 4:10 am UTC

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Physics

The displacement of water is an excellent way to measure the volume of a solid provided that the solid does not dissolve in water and that it does not float. If the object floats then it will not...

Latest answer posted September 22, 2012 3:55 am UTC

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Physics

Thte way you have worded this, the ball is below the ceiling, so the potential energy with respect to the ceiling is negative. PE = mgh, and since the zero position is the ceiling, the potential...

Latest answer posted November 22, 2009 10:15 am UTC

2 educator answers

Physics

Most of the time, people ask this question with the idea of a Newtonian "feather vs. bowling ball" concept in mind. Based on those terms, the typical answer is correct: two objects will fall at the...

Latest answer posted July 11, 2014 4:34 am UTC

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Physics

The term "relative density" means the same as "specific gravity." It is a measure of how dense one thing is when compared to a given reference. The reference is usually water. With respect to...

Latest answer posted December 15, 2009 11:13 am UTC

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Physics

A 23.8 g silver ring (cp = 234 J/kg*C) is heated to a temperature of 82.2 C and then placed in a calorimeter containing 5.32*10^-2 kg of water at 24.0 C. The calorimeter is not perfectly insulated...

Latest answer posted February 12, 2012 12:55 am UTC

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Physics

Forces are considered balanced when all of the combined forces lead to no change in the motion of the object. For example, when a book is sitting on a table, the force of gravity is pushing...

Latest answer posted November 14, 2008 4:45 am UTC

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Physics

A 145 g baseball is thrown with a speed of 25 m/s. When the thrower picks up the ball it is at rest. When it leaves the hand of the person that is throwing the ball it has a speed of 25 m/s. An...

Latest answer posted March 26, 2012 11:26 am UTC

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Physics

To determined the height of the tower a pendulum is created by tying a rock to a thread and hanging it from the ceiling of the tower. The period of the pendulum us found to be 9.18 s. The period of...

Latest answer posted February 13, 2012 11:38 am UTC

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Physics

The initial momentum of the small object is 5 kg*m/s towards the larger object that is at rest. After collision, the small object bounces back with a momentum that has a magnitude or 4 kg*m/s. As...

Latest answer posted July 1, 2012 4:38 pm UTC

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Physics

If I understand this question correctly, the angle of reflection should be 30 degrees with respect to the mirror as well. The angle of the incoming ray and the angle of the ray that is reflected...

Latest answer posted March 31, 2010 10:55 pm UTC

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Physics

The Young's modulus is a constant for metals in the range of values of stress for which Hooke's law is valid. It can be determined by the relation: Young's modulus= Tensile Stress/ Tensile Strain....

Latest answer posted November 18, 2010 7:39 pm UTC

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Physics

Power is defined as the ratio of work per time, or 1. Power = Work/Time Work is defined as Force times Displacement, or 2. Work = Force * Displacementso therefore3. Power = (Force * Displacement) /...

Latest answer posted November 28, 2008 10:52 am UTC

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Physics

When a body is placed in a fluid, there is an upward force exerted on the body that is equal to the weight of the fluid displaced by it as it sinks into the fluid. When this force is equal to the...

Latest answer posted June 2, 2012 3:14 pm UTC

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Physics

The following formula relates object distance, image distance, and focal length for convex mirrors: 1/(focal length) = 1/(object distance) + 1/(image distance) or 1/fo = 1/do + 1/di The image...

Latest answer posted May 18, 2011 7:52 am UTC

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Physics

The car is initially traveling at 25 m/s. When the brakes are applied there is a resistive force that leads to a decrease in the velocity of the car and it eventually comes to a stop. The weight of...

Latest answer posted May 8, 2011 12:51 pm UTC

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Physics

The pressure acting on a surface is determined by the force acting on a unit area of the surface. At sea level the standard pressure exerted by the atmosphere or 1 atm = 101325 Pa. Pascal is a unit...

Latest answer posted February 3, 2012 12:01 pm UTC

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Physics

A physical system that can do work on other physical systems has an amount of energy that is equal to the work that can be done. For example, a compressed spring can do work on another body when it...

Latest answer posted November 17, 2011 10:55 am UTC

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Physics

The ball is thrown upwards at 96 ft/s from the roof of a building which is 64 foot tall. The height of the ball after t seconds is given by the function: s(t) = 64 + 96t - 16t^2 To find the maximum...

Latest answer posted February 22, 2011 2:01 pm UTC

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Physics

A hockey stick is used as a lever. When you hold a hockey stick, the hand with which you hold the stick at the top end serves as the fulcrum. The other hand with which you catch the stick in the...

Latest answer posted November 10, 2011 3:04 pm UTC

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Physics

This needs the basic understanding of rotational dynamics. Kinetic energy of a rotating mass is KE = (I * w^2)/2 where I is the moment of inertia and w (omega) is the rotational velocity in...

Latest answer posted May 1, 2012 7:53 pm UTC

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Physics

The angle of projection for which the maximum height of the projectile is equal to the horizontal range has to be determined. Let the required angle of projection be A and object is projected at V...

Latest answer posted February 16, 2012 10:29 am UTC

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Physics

The height of mercury above the bowl in a barometer is a measure of the pressure of air pushing on the mercury in the bowl. The mass of the mercury above the bowl times the force of gravity is...

Latest answer posted December 28, 2009 9:39 pm UTC

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Physics

The worker on the roof of the house drops his 0.83kg hammer, which slides down the roof at constant speed of 8.55m/s. The angle made by the roof with the horizontal is 21 degrees and its lowest...

Latest answer posted February 1, 2012 1:19 am UTC

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Physics

The hockey puck has a mass 0.16 kg. It starts from rest and reaches a speed of 22 m/s, during which the distance traveled is 1.2 m. Initially the puck has no kinetic energy. After 1.2 m the kinetic...

Latest answer posted December 2, 2012 9:24 am UTC

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Physics

Water absorbs heat in the electric kettle and increases in temperature. It soon reaches the boiling point once enough heat has been absorbed. The heat produced in the electric kettle is due to the...

Latest answer posted October 12, 2011 2:00 pm UTC

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Physics

The meaning of the original statement is that if you have a cubic meter of water (an amount of water that is one meter in height, one meter in width, and one meter in depth), that amount of water...

Latest answer posted December 15, 2009 12:02 am UTC

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Physics

The formula for gravitational attraction is Fg = (Gm1m2)/r^2 In this formula, G is the Universal Gravitational Constant while m1 and m2 are the masses of the two bodies. R is the distance of...

Latest answer posted November 22, 2009 11:02 pm UTC

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Physics

The rope pulls the 2.0 kg buckets vertically upwards accelerating it from rest at 2.2 m/s^2 for 3 seconds. In 3 seconds, the distance traveled by the bucket is equal to s = u*t + (1/2)*a*t^2. Here...

Latest answer posted November 28, 2012 9:08 am UTC

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Physics

I think justaguide meant to use V*sin60 in the first calculation so all the values are vertical ones. At the top of the trajectory when it "just" gets into the window it will have 0 vertical...

Latest answer posted February 17, 2012 9:56 am UTC

2 educator answers

Physics

I hope you know that when the rays from an object fall on any mirror (concave convex or plane), an image is formed. In case of a place mirror, the object is placed in front of the mirror and image...

Latest answer posted November 18, 2012 4:35 pm UTC

1 educator answer

Physics

The pressure would be doubled if the same force acted on half the area. The pressure in the first scenario is 50 N/m^2 while the pressure in the second scenario is 100 N/m^2 The way you get this is...

Latest answer posted February 1, 2010 1:26 pm UTC

1 educator answer

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