Wednesday

November 25, 2015
Total # Posts: 386

**physics**

Assume a cyclist of weight mg can exert a force on the pedals equal to 0.90 mg on the average. If the pedals rotate in a circle of radius 18 cm, the wheels have a radius of 34 cm, and the front and back sprockets on which the chain runs have 42 and 19 teeth respectively (Fig. ...
*November 16, 2015*

**universitu**

A tire 0.50meter in radius rotates at aconstant rate of 200 revolution per minute .find the speed & accelaration of asmall stone lodged in the tread of the tire(on its outer edge)
*November 5, 2015*

**Crystal**

So this is the problem: A comet is in an elliptical orbit around our Sun. At its point of closest approach, it is moving at 6.3x10^4 m/s and is 4.2x10^10m away from the sun. When it is at the farthest distance, 7.5x10^12m away, how fast is it going? This is what I did K1+U1=K2...
*November 4, 2015*

**mastering physics**

An airplane pilot wishes to fly due west. A wind of 90.0 km/h is blowing toward the south.If the airspeed of the plane (its speed in still air) is 305.0 km/h , in which direction should the pilot head?
*October 29, 2015*

**physics**

You are driving on a very long, very straight 2 lane road, stuck behind a lorry which travels at a constant 75 km/hour. You want to overtake the lorry, which has a length of 12.0 m. You car is 3.8 m long. To overtake the lorry, and to do this safely, you need to move to the ...
*October 17, 2015*

**Honors Physics **

Emily makes 0.250 kg of hot tea at 99.0°C. How much ice at 0.00°C must she add to the tea so that the mixture reaches a final temp. of 8.00°C? (You may treat the tea as if its water.) My work: (0.25)(4186)(91) + m(4186)(-8)(3.35 ×10^5)=0 My answer: 0.316 It ...
*June 1, 2015*

**science**

the resultant of two forces 13n and 20 n is f if the first forces is doubled the resultant is also doubled to 2f find the angle betwen the two forces
*May 18, 2015*

**PHYSICS**

Consider a classroom 10.0m long by 6.0m wide by 4.0m high at "room temperature" 20.C and 1.0 atmosphere. A) How many moles of gas are contained in the room? B) Assuming an average molecular weight of 28, what is the mass of the room air?
*May 7, 2015*

**quantum**

Consider a particle with mass m bound to a potential v(x) = k^2|x|. Using the WKB quantization condition, find the energy eigenvalues .
*April 4, 2015*

**PHYSICS**

The gravitational forces of the Earth and the Moon are attractive, so there must be a point on a line joining their centers where the gravitational forces on an object cancel. How far is this distance from the Earth's center?
*March 15, 2015*

**Marianne**

Fill in the blank: The electrons follow a ________ path when they are deflected in a magnetic field due to the magnetic force.
*March 13, 2015*

**science**

A sandbag falls from a hot air balloon that is rising with a constant velocity of 15m.s 1)What is the acceleration of the bag the moment it fell from the hot air balloon? 2)What is the acceleration of the hot air balloon the moment the sandbag fell from it? 3)What is the ...
*March 1, 2015*

**physics**

find the resistance of 134m of No.20 copper wire at 20 degrees C (p=1.72x10^-6Ohom cm , A= 2.07x10^-2 cm ^2)
*February 11, 2015*

**physics**

what is the electric force exerted on a test charge of 3.86 x 10^-5 C if it is placed in an electric field of magnitude 1.75 x 10^4 N/C ?
*February 11, 2015*

**Selam **

A real object is placed in front of a diverging lens, at a distance less than the focal length. When the object is moved slightly closer to the lens, which direction does the image move? away from the lens. doesn't move. closer to the lens. -- I know this is the answer But...
*January 21, 2015*

**tsion**

Determine whether each of the following statements is true or false. A concave mirror never forms an enlarged real image of a real object. >true A virtual image formed by a concave mirror is always smaller than the real object. >false A reduced image formed by a concave ...
*January 21, 2015*

**physics **

When a wave crosses a boundary between a thin and a thick rope, its frequency changes, but its wavelength and speed do not. True or false I think the answer is True
*November 23, 2014*

**PLEASE HELP PHYSICS**

Ok.
*November 23, 2014*

**projectives**

A cannon ball is fired horizontally with a velocity of 50m/s from the top of a cliff of 90mh. after how many seconds will it strike the plane at the foot of the cliff and at what distance at the foot of the cliff will it strike?
*November 9, 2014*

**Physics**

exam question
*November 3, 2014*

**n. i. o. s physics**

How would you design a black body?
*October 26, 2014*

**physics**

Two objects with masses 2.0 and 3.0 kg move toward each other, both with speeds V0 = 5.0 m/s. They collide head on and stick together. (a) Calculate their final velocity. (b) Calculate the amount of kinetic energy lost during the process. (c) Suppose the two masses approach ...
*September 6, 2014*

**physics**

How much heat is added to 10.5 g of ice at -20.0°C to convert it to steam at 123.5°C?
*May 26, 2014*

**help**

A sound wave travels at 343 m/s and a compression passes by every 12 ms. What is the wavelength of this sound?
*May 4, 2014*

**Physics**

A car with a mass of 900 kg moves along a road at a 89 km/hour at equal speed. On the road is a curve with a radius of 250. a) What is the force in the curve between the tires and the road if the road is horizontal? b) What inclination is the best for that car on the road...
*March 11, 2014*

**PHYSICS PLEASE HELP**

A fire hose held near the ground shoots water at a speed of 6.5 m/s 1. At what angle(s) should the nozzle point in order that the water land 2.5 m away? -I believe the answer is 18,72 2. Sketch the trajectory for the 18; angle -Please give me exact (x,y coordinates) -I believe...
*January 26, 2014*

**Physics**

A pair of constant forces of magnitude F = 11.1 N is applied to opposite sides of the axle of a top, as shown in the figure. The diameter of the axle is d = 8.67 mm. The angle è, which has a value of 36.1°, describes the steepness of the top's sloping sides. The...
*December 10, 2013*

**Calculus Inegral**

integral of x/lnx
*November 14, 2013*

**physics**

A 0.0309-kilogram ball is stuffed into a spring gun and shot up into the air at some angle. The gun's spring has a force constant of 92.5 N/m and is initially compressed 0.138 m. When the ball reaches maximum height, it has a horizontal velocity with a speed of 2.23 m/s. ...
*November 11, 2013*

**Physics**

a 15-kg box is resting on a hill forming an angle with the horizontal. The coefficient of static friction for the box on the surface is 0.45. calculate the maximum angle of the incline just before the box starts to move
*October 30, 2013*

**Help!!**

An air-filled capacitor consists of two parallel plates, each with an area of 7.60 cm2, separated by a distance of 1.70 mm. (a) If a 16.0 V potential difference is applied to these plates, calculate the electric field between the plates. kV/m (b) What is the surface charge ...
*October 17, 2013*

**motion,physics**

Model rockets are lightweight rockets powered by very small engines. A typical model rocket has a mass of 5g.Similarly, a typical "class C" model rocket engine can produce a total impulse of 10 Newton-seconds. We usually launch model rockets vertically, but if I ...
*October 11, 2013*

**physics**

We are standing at a distance d=15 m away from a house. The house wall is h=6 m high and the roof has an inclination angle β=30 ∘. We throw a stone with initial speed v0=20 m/s at an angle α= 35 ∘. The gravitational acceleration is g=10 m/s2. (See figure...
*October 6, 2013*

**PHYSICS**

We are standing at a distance d=15 m away from a house. The house wall is h=6 m high and the roof has an inclination angle β=30 ∘. We throw a stone with initial speed v0=20 m/s at an angle α= 35 ∘. The gravitational acceleration is g=10 m/s2. (See figure...
*October 6, 2013*

**Physics**

no but how did you get it?
*October 6, 2013*

**Physics**

did you manage to solve it
*October 6, 2013*

**PHYSICS**

Two protons in a molecule are 3.80 multiplied by 10-10 m apart. Find the electrical force exerted by one proton on the other. Magnitude N (b) State how the magnitude of this force compares with the magnitude of the gravitational force exerted by one proton on the other. (...
*September 29, 2013*

**PHYSICS**

A rod 14.0 cm long is uniformly charged and has a total charge of -20.0 ÂµC. Determine the magnitude and direction of the electric field along the axis of the rod at a point 36.0 cm from its center. N/C
*September 29, 2013*

**PHYSICS**

A rod 14.0 cm long is uniformly charged and has a total charge of -20.0 ÂµC. Determine the magnitude and direction of the electric field along the axis of the rod at a point 36.0 cm from its center. N/C
*September 28, 2013*

**PHYSICS**

Two protons in a molecule are 3.80 multiplied by 10-10 m apart. Find the electrical force exerted by one proton on the other. Magnitude N (b) State how the magnitude of this force compares with the magnitude of the gravitational force exerted by one proton on the other. (...
*September 28, 2013*

**PHYSICS**

A rod 14.0 cm long is uniformly charged and has a total charge of -20.0 ÂµC. Determine the magnitude and direction of the electric field along the axis of the rod at a point 36.0 cm from its center. N/C
*September 28, 2013*

**college physics**

Two protons in a molecule are 3.80 multiplied by 10-10 m apart. Find the electrical force exerted by one proton on the other. Magnitude N (b) State how the magnitude of this force compares with the magnitude of the gravitational force exerted by one proton on the other. (...
*September 28, 2013*

**physics**

A spectral line is emitted when an atom undergoes tranisition between two levels with a difference in energy of 2.4eV.What is the wavelength of the line (a)287nm(b)507angstrome units()377angstrome units(d)518nm
*September 22, 2013*

**physics**

A current flows in a wire of circular cross-section with the free electrons travelling with a mean drift velocity v. If an equal current flows in a wire of the same material but of twice the radius,what is the new mean drift velocity (a)v/4(b)v/2(c)2v(d)4v
*September 22, 2013*

**physics**

When a parachute opens, the air exerts a large drag force on it. This upward force is initially greater than the weight of the sky diver and thus slows him down. Suppose the weight of the sky diver is 905 N and the drag force has a magnitude of 1005 N. The mass of the sky ...
*August 21, 2013*

**Justin**

Four identical metallic spheres with charges of +2.2 µC, +8.2 µC, −4.6 µC, and −9.2 µC are placed on a piece of paper. The paper is lifted on all corners so that the spheres come into contact with each other simultaneously. The paper is then...
*August 19, 2013*

**Justin**

If 2.00 X 10^20 electrons move through a pocket calculator during a full day's operation, how many coulombs of charge moved through it?
*August 19, 2013*

**WIP**

A softball bat is rotating at 460 rotations per minute at contact with the ball. What is the angular velocity in radians?
*August 6, 2013*

**velocity**

what does velocity mean in physics?
*July 15, 2013*

**science**

a machine gun can fire 20 bullet persecond if speed of bullet is 100m/s and if each bullet weight 100grams calcuate force required to hold the gun in its position
*June 30, 2013*

**sam**

How much do you do if you push a garbage can with a force of 30N while sliding it 4 meters down the hall?
*May 29, 2013*

**Sam**

Is work being done by an ocean wave as ;it hits a dock with a force of 1000N?
*May 29, 2013*

**Physics**

Any one please ans this answer. The circuit below consists of three identical resistors each with resistance R=37 Ohm, two identical batteries with emfs E=25 V, and a capacitor with capacitance C=401 μF. The capacitor is initially uncharged at t = 0. (a) After a very very...
*May 22, 2013*

**Physics**

TA please give ans or formula for any ques tion you have got. 1c is 1.5*V V is volatage of the battery.
*May 22, 2013*

**Physics**

GR my values for Ques1 d part are V=25 C=401 R=37
*May 22, 2013*

**physics**

An alpha-particle collides with an oxygen nucleus which is initially at rest. The alpha-particle is scattered at an angle of 67.0 degrees from its initial direction of motion, and the oxygen nucleus recoils at an angle of 52.0 degrees on the other side of this initial ...
*April 24, 2013*

**physics**

An alpha-particle collides with an oxygen nucleus which is initially at rest. The alpha-particle is scattered at an angle of 67.0 degrees from its initial direction of motion, and the oxygen nucleus recoils at an angle of 52.0 degrees on the other side of this initial ...
*April 24, 2013*

**k**

Two wires parallel to each other and seperated by a distance d carry different currents; they exert a force with magnitude F on each other. (a) The wires carry current in opposite directions. If the current carried by both wires is divided by five and the distance between the ...
*April 15, 2013*

**physics**

A roller-coaster car has a mass of 1100 kg when fully loaded with passengers. As the car passes over the top of a circular hill of radius 20 m, its speed is not changing. (a) At the top of the hill, what is the normal force (using the negative sign for the downward direction) ...
*March 9, 2013*

**Physics**

A uniform ladder weighing 197 N is leaning against a wall. The ladder slips when θ = 63.0°. Assuming that the coefficients of static friction at the wall and the ground are the same, obtain a value for µs.
*February 15, 2013*

**Ronit**

What is the current through a wire if 240 coulombs of charge pass through the wire in 2.0 minutes?
*February 10, 2013*

**Physics question**

A rope suspended from a ceiling supports an object of weight W at its opposite end. Another rope tied to the first at the middle is pulled horizontally with a force of 30N.the junction P of the rope is in equilibrum. Calculate the weight W and the tens.
*February 8, 2013*

**Physics question**

A boy intend to move an mkg crate across the floor by applying a constant force p newton on it.the coeficient of friction between the floor and crate is ü.which of these is the best option for his task?
*February 8, 2013*

**Science**

A 6 kg grinding wheel of radius 0.2 m rotates at a constant rotational frequency of 4 rad/s when an object makes contact with the outer edge of the wheel. Friction causes the wheel to stop in 2 seconds. What is the average torque on the wheel by the frictional force?
*February 5, 2013*

**Physics**

A 6 kg grinding wheel of radius 0.2 m rotates at a constant rotational frequency of 4 rad/s when an object makes contact with the outer edge of the wheel. Friction causes the wheel to stop in 2 seconds. What is the average torque on the wheel by the frictional force?
*February 5, 2013*

**5th grade math**

To find out how many bows Alicia can make, divide 4 yards by 1/3 and you will get the answer that Victoria provided.
*February 4, 2013*

**math6**

I presume that all you have to do is divide the amount of miles that she drove by how long she drove. 621miles/11.5hours=54miles/hour
*February 4, 2013*

**Melanie**

A right triangle has a hypotenuse of length 13 meters and one side of length 5 meters. What is the length of the third side and the angle between the hypotenuse and the 5 meter side? A. 144 meters, 67.38 degrees B. 12 meters, 22.62 degrees C. 10 meters, 22.62 degrees D. 12 ...
*January 19, 2013*

**physics**

A car with a mass of 3200 kg and a velocity of 50 m/s brakes to a final velocity of 25m/s in a distance of 85 m. what is the force the brakes apply to stop the car.
*January 15, 2013*

**physics**

A hiker, who weighs 1120 N, is strolling through the woods and crosses a small horizontal bridge. The bridge is uniform, weighs 3775 N, and rests on two concrete supports, one at each end. He stops one-fifth of the way along the bridge. What is the magnitude of the force that ...
*December 10, 2012*

**physics **

In an arcade game a 0.135 kg disk is shot across a frictionless horizontal surface by compressing it against a spring and releasing it. If the spring has a spring constant of 155 N/m and is compressed from its equilibrium position by 7 cm, ﬁnd the speed with which the ...
*November 28, 2012*

**Physics**

A basketball of mass 0.70 kg is dropped from rest from a height of 1.22 m. It rebounds to a height of 0.64 m. How much mechanical energy was lost during the collision with the floor? A basketball player dribbles the ball from a height of 1.22 m by exerting a constant downward ...
*November 27, 2012*

**physics**

Exactly 11 kJ of energy was absorbed by 1 mol of Cl2(g) at 298 K. What i s thefinal temperature of the Cl2(g)? The heat capacity of Cl2(g) is 25.635J.K-1.mol-1
*September 25, 2012*

**Taylor**

The blck mamba is one of the world's most poisonous snakes, and with a maximum speed of 18.0 km/h, it is also the fastest. Suppose a mamba waiting in a hide-out sees prey and begins slithering toward it with a velocity of +18.0 km/h. After 2.50 s, the mamba realizes that ...
*September 23, 2012*

**physics**

Boring physics
*July 20, 2012*

**Physics need work checked**

Physics lenses. Please help, my math is wrong and I need second opinion.? Consider three lenses with focal lengths of 25.9 cm, -15.8 cm, and 10.0 cm positioned on the x axis at x1 = 0 m, x2 = 0.412 m, and x3 = 0.514 m, respectively. An object is at d = -121 cm. Find the ...
*May 2, 2012*

**help**

from which equations is the following equation derived from: length=(time^2 * g)/4
*April 4, 2012*

**emily**

What is the potential halfway between two point charges spaced 1 mm apart if q1=10 micro culumbs and q2= -5 micro culumbs
*February 15, 2012*

**jane**

In an electric field described by E = (20i+60j) V/m calculate the change in potential for a particle that moves from the origin to the coordinates (3,3)m
*February 15, 2012*

**TOm**

Hello, this is the last question that I can't seem to or be able to solve: 1. Jenny (75 kg) goes on a ski trip. She goes down a slope that's inclined at 15*. The drag coefficient of Jenny is 0.300, the surface of contact with air is 0.750 m^2 and the air density is 1,...
*January 27, 2012*

**electric force/field**

Three point charges, A = 2.2 µC, B = 7.5 µC, and C = -3.9 µC, are located at the corners of an equilateral triangle . Find the magnitude and direction of the electric field at the position of the 2.2 µC charge. magnitude = . N/C direction =
*January 23, 2012*

**victor.M**

What is the resulting temperature when a 150g cube of ice at zero degrees is added to 200g of water in a aluminium cup at 30 degrees
*January 12, 2012*

**A man wants to cross a river 500 m wide which flows at speed of 2 km/hr.the man rows a boat perpendicular to the river flow at 3 km/hr relative to the river.what is relative velocity of boat relative to the ground?**

Velocity of boat relative to the river(vbr):3 km/hr, velocity of river relative to ground(vrg) :2 km/hr. Velocity of boat relative to the ground(vbg): square root of 9+4
*November 20, 2011*

**Physics 101**

The systemis in equilibrium and the pulleys are frictionless and massless. |_________________________| l l l ( . ) l / \ | / \ ( . ) 8kg | I 2kg ( . ) | / \ | I 6kg ______V____I____________________ _________________________________| Find the force T. The acceleration of ...
*November 8, 2011*

**physics101**

A uniform 7.1 m tall aluminum ladder is leaning against a frictionless vertical wall. The ladder has a weight of 272 N. The ladder slips when it makes a 57.0degrees angle with the horizontal floor. Determine the coefficient of static friction between the ladder and the floor.
*November 7, 2011*

**physics**

A boat moves through the water with two forces acting on it. One is a 2.80×10 3 N forward push by the motor, and the other is a 1.56×10 3 N resistive force due to the water. a)What is the acceleration of the 1312.6 kg boat? Answer in units of m/s^2 b)If it starts ...
*October 23, 2011*

**physics 911**

A force ~F = Fx ˆı+Fy ˆ| acts on a particle that undergoes a displacement of ~s = sx ˆı + sy ˆ| where Fx = 10 N, Fy = −1 N, sx = 5 m, and sy = 3 m. Find the work done by the force on the particle. Answer in units of J b) Find the angle ...
*October 15, 2011*

**physics**

I think it's saying only gravity is affecting the particle on the y-axis.
*September 25, 2011*

**physics**

The vertical acceleration is 9.8 m/s^2 because of gravity. So in the negative y direction.
*September 25, 2011*

**physics**

Initially (at time t = 0) a particle is moving vertically at 5.8 m/s and horizontally at 0 m/s. Its horizontal acceleration is 2.1 m/s2. At what time will the particle be traveling at 54 with respect to the horizontal? The acceleration due to gravity is 9.8 m/s2.
*September 25, 2011*

**physics**

A linear charge of nonuniform density E(x)=bx C/m, where b = 5.2 nC/m2, is distributed along the x-axis from 4.9 m to 6 m. Determine the electric potential (relative to zero at infinity) of the point y = 8.6 m on the positive y-axis.
*September 24, 2011*

**physics**

The electric potential in a certain region is V = a x2 + b x + c, where a = 15 V/m2, b = −13 V/m, and c = 67 V. 1)Determine the electric field at x = 4 m. 2)Determine the position where the electric field is zero.
*September 24, 2011*

**physics**

A linear charge of nonuniform density (x) = 5.2 x C/m, is distributed along the x-axis from 4.9 m to 6 m. Determine the electric potential (relative to zero at infinity) of the point y = 8.6 m on the positive y-axis. Answer in units of V
*September 24, 2011*

**physics**

A charge of 10.104 nC is uniformly distributed along the x-axis from −1 m to 1 m. What is the electric potential (relative to zero at infinity) of the point at 5 m on the x-axis?
*September 24, 2011*

**physics**

A place kicker must kick a football from a point 36 m (about 39 yd) from the goal, and the ball must clear the crossbar, which is 3.05 m high. When kicked, the ball leaves the ground with a speed of 24 m/s at an angle of 50 to the horizontal. The acceleration of gravity ...
*September 24, 2011*

**physics**

Particle 1 is moving on the x-axis with an acceleration of 5.55 m/s2 in the positive x-direction. Particle 2 is moving on the y-axis with an acceleration of 7.45 m/s2 in the negative y-direction. Both particles were at rest at the origin at t = 0 s. Find the speed of particle ...
*September 24, 2011*

**physics**

Initially (at time t = 0) a particle is moving vertically at 5.8 m/s and horizontally at 0 m/s. Its horizontal acceleration is 2.1 m/s2. At what time will the particle be traveling at 54 with respect to the horizontal? The acceleration due to gravity is 9.8 m/s2. Answer ...
*September 24, 2011*

**Ida**

What does duracell manufacture say about the durability of their brand
*July 24, 2011*

**physics...........**

What is the probability that the bulb is glowing for a circuit set up as: |-------------(Bulb)-----------| | | | | (Voltage) | | | | | |----(Switch-1)---(Switch-2)---|
*June 25, 2011*