Saturday

August 30, 2014

August 30, 2014

**Recent Homework Questions About Physics**

Post a New Question | Current Questions

**physics**

The exhaust temperature of a heat engine is 250∘C .What must be the high temperature if the Carnot efficiency is to be 35% ?
*Wednesday, June 4, 2014 at 9:53pm*

**physics**

a pole 10m long rests slantly against a vertical wall ab making 60 degrees with the horizontal (ground). find how faris the foot of the pole from the wall
*Wednesday, June 4, 2014 at 9:26pm*

**physics**

A charge of -2.68 ✕ 10-9 C is at the origin of a coordinate system, and a charge of 7.77 ✕ 10-9 C is on the x-axis at 2.00 m. At what two locations on the x-axis is the electric potential zero? (Hint: One location is between the charges, and the other is to the ...
*Wednesday, June 4, 2014 at 9:16pm*

**physics**

During the Olympic ice competition, Boris (m = 75 kg) glides at 1.8 m/s to a stationary Juliette (52 kg) and hangs on. How far will the pair slide after the collision if the coefficient of kinetic friction between the ice and their skates is .042?
*Wednesday, June 4, 2014 at 8:44pm*

**physics**

A 1.0 kg puck sliding at 15 m/s along some horizontal frictionless ice strikes and compresses a horizontal spring attached to one end of the ice rink. If the spring has a constant of 35 N/m, what is the maximum compression of the spring?
*Wednesday, June 4, 2014 at 8:41pm*

**physics**

A collision in Phystown is being analyzed by the O.P.P. accident analysis team. A 1000 kg Toyota known to be moving at 65 km/h [W] collided at an intersection with a 3000 kg SUV moving [N]. After the collision, the two vehicles "stuck" together and the police ...
*Wednesday, June 4, 2014 at 8:28pm*

**Physics**

A football player punts the ball at a 45.0o angle. Without an effect from the wind, the ball would travel 60.0 m horizontally. (a) What is the initial speed of the ball? (b) When the ball is near its maximum height it experiences a brief gust of wind that reduces its ...
*Wednesday, June 4, 2014 at 8:25pm*

**Physics**

A 250g wood block firmly attached to a horizontal spring slides along a table with a coefficient of friction of 0.40. A force of 30.N compresses the spring 20cm. If the spring is released from this position what will be the block's speed when it passes equilibrium position?
*Wednesday, June 4, 2014 at 8:14pm*

**physics**

A horizontal spring with spring constant of 120 N/m is compressed a distance of 0.25 m and placed in front of a ramp angled at 30° above the horizontal. A 1.5 kg ball is placed in front of it and released. How far will the ball roll up the 30° ramp? Again assume there ...
*Wednesday, June 4, 2014 at 7:51pm*

**physics**

A 2.2 kg bowling ball is dropped vertically from a height of 1.5 m onto a long compression spring (k = 150 N/m) placed vertically underneath it. What is the maximum compression of the spring?
*Wednesday, June 4, 2014 at 7:45pm*

**physics**

A 2.0 kg mass is fastened to a spring with force constant of 45 N/m. The mass is held motionless by a student at a position 15 cm below the spring's natural unstretched position. When the ball is released, what is the Fnet acting on it? What is the acceleration of the ball...
*Wednesday, June 4, 2014 at 7:13pm*

**Physics**

A ball is thrown straight upward and returns to the thrower's hand after 2.30 s in the air. A second ball is thrown at an angle of 42.0° with the horizontal. At what speed must the second ball be thrown so that it reaches the same height as the one thrown vertically?
*Wednesday, June 4, 2014 at 7:12pm*

**Physics**

Help me with this please A 6.0 m section of wire carries a current of 5.2 A from east to west in the earth's magnetic field of 1.0 × 10^-5 T at a location where the magnetic field points south. In which direction does the magnetic force act on the wire? north south ...
*Wednesday, June 4, 2014 at 6:30pm*

**Physics**

A soccer ball is kicked with a speed of 9.95m/s at an angle of 35.0∘ above the horizontal.If the ball lands at the same level from which it was kicked, how long was it in the air?
*Wednesday, June 4, 2014 at 6:22pm*

**Physics**

A small charge that has lost 5.0 X 10^3 electrons and has a mass of 2.0 x 10^-6 kg experiences an acceleration of 15ms^2 when placed at a point P in space. Determine the magnitude and direction of the electric field at P
*Wednesday, June 4, 2014 at 6:19pm*

**Physics**

The length of a box is reduced to two third of its original value and the width and height are tripled. Calculate the factor by which the volume has changed. Am I on the right track? If not please help I am stuck. Thanks. V=LWH V=(L-2/3)(3W)(3H)
*Wednesday, June 4, 2014 at 6:13pm*

**physics**

A 55 kg skateboarder accelerates down a ramp and hits the pavement moving at 5.6 m/s. If the pavement has a coefficient of friction of 0.11, how far will skateboarder glide before coming to a stop?
*Wednesday, June 4, 2014 at 5:35pm*

**physics**

4 kg block rests on a smooth horizontal surface,upper surface of 4 kg is rough.A block of mass 2 kg is placed on its upper surface.The acceleration of upper block with respect to earth when 4 kg mass is pulled by a horizontal force of 30N?coefficient of static friction=0.8 and...
*Wednesday, June 4, 2014 at 4:26pm*

**physics**

What is the kinetic energy of a 19 kg dog that is running at a speed of 7.7 m/s (about 17 mi/h)?
*Wednesday, June 4, 2014 at 3:23pm*

**physics**

"a drag racing car starts from rest at t= 0 and moves along astraight line with velocity given by V = bt^2 where b isconstant. The expression for the distance traveled by this car from its position at t = 0 is a)bt^3 b)bt^3/3
*Wednesday, June 4, 2014 at 2:08pm*

**Physics ||**

Q.1. Two wires each of length 40 m and diameter 2.6 mm, are connected in series. A potential difference of 50 V is applied between the ends of the composite wire. The resistances the wires are 0.13 Ω and 0.75 Ω, respectively. Determine: i) the current density in each...
*Wednesday, June 4, 2014 at 10:07am*

**physics**

a person walks due east for 10 meters and the due north for 10 meters. what is the total distance? b). what is the average speed of a car that travels 30 meters in 10 seconds, then another 50 meters in 30 seconds. Thank you for answering.
*Tuesday, June 3, 2014 at 11:14pm*

**Physics I NEED HELP WITH EQUATIONS**

A 7kg block is pulled at a constant velocity by a horizontal 25 N force - Calculate normal & gravitational forces - Calculate the applied & frictional forces - Calculate the coefficient of friction CAN SOMEONE PLEASE HELP ME WITH THE EQUATIONS FOR ALL OF THESE THINGS?
*Tuesday, June 3, 2014 at 10:55pm*

**physics**

a person walks due east for 10 meters and then due north for 10 meters. what is the total displacement?
*Tuesday, June 3, 2014 at 10:37pm*

**Physics**

i have a question on thin lens equation how do i know when di is positive or negative? also i have an example: A convex lens has a focal length of 60 cm. A candle is placed 50 cm from the lens. What type of image is formed and how far is the image from the lens? (Is my answer ...
*Tuesday, June 3, 2014 at 9:18pm*

**physics**

Two wires are made of the same material. The first wire dissipates power P with a current of I. If the second wire is 3 times as long and has twice the diameter, what will the current need to be through the second wire to dissipate the same power P as the first wire? A ...
*Tuesday, June 3, 2014 at 8:58pm*

**Physics**

Determine the final velocity of an alpha particle (3.2x10^-19) if it is placed in a 7.2x10^6 n/c uniform field. The mass of the alpha particle is 6.64x10^-27
*Tuesday, June 3, 2014 at 8:51pm*

**Physics**

Which of the following is an appropriate measure of electric power on a toaster label? A. 110 V B. 2.0 A C. 220 W D. 55 Ω
*Tuesday, June 3, 2014 at 8:41pm*

**physics**

In a rescue scene during the 911 crisis, a helicopter of mass 6000 kg accelerates upwards at the rate of 0.50 m/s2 while lifting a 2500 kg piece of concrete. What is the upward force exerted by the rotors of the helicopter? What is the tension in the cable attaching the ...
*Tuesday, June 3, 2014 at 8:37pm*

**Physics**

Am i correct? If a 10.0 kW device pulls 20.0 A of current, what voltage exists across it? A. 5.0 *10^0 V B. 5.0 *10^1 V C. 5.0 *10^2 V D. 5.0 *10^3 V <---
*Tuesday, June 3, 2014 at 8:08pm*

**physics**

A ball on the end of a string is moving in a horizontal circle. If the centripetal acceleration of the ball is 12 m/s2, while it is travelling at 3.0 m/s, what would the acceleration be if its speed increased to 4.0 m/s. Assume that the radius of rotation does not change.
*Tuesday, June 3, 2014 at 7:55pm*

**Physics**

What is the equivalent resistance of a parallel circuit with a 5.0 kΩ resistor, a 2.5 kΩ resistor, and 10.0 kΩ resistor? A. 0.10 kΩ b. 0.83 kΩ c. 10 kΩ d. 1.4 kΩ e. 18 kΩ
*Tuesday, June 3, 2014 at 7:49pm*

**Physics**

One 10.0 Ω resistor is wired in series with 10.0 Ω resistors in parallel. A 45.0 V battery supplies power to the circuit. What is the total current through the circuit? A. 3.0 A B. 1.5 A C. 0.75 A D. 0.33 A
*Tuesday, June 3, 2014 at 7:28pm*

**Physics**

Help me with this please A 10.0 Ω resistor is in parallel with a 20.0 Ω resistor and supplied by a 9.00 V battery. What is the total current passing through the circuit? A. 0.38 A B. 0.75 A C. 1.35 A D. 6.00 A
*Tuesday, June 3, 2014 at 6:48pm*

**physics**

A fisherman who lives in a high rise apartment building in Toronto, weighs a fish on a spring scale and records a 11.2 N reading. He reweighs the fish while he is in his elevator and records a reading of 13.1 N. What is the acceleration of the elevator at that moment?
*Tuesday, June 3, 2014 at 6:14pm*

**physics**

Sarah is pushing a 10 kg buggy and exerts a force of 100 N along the handle. If the handle is elevated at 37° to the horizontal, determine the component of the force that will move the buggy forward. If a frictional force of 60 N exists as she pushes it over a grass ...
*Tuesday, June 3, 2014 at 5:27pm*

**physics**

Calculate the average velocity for a remote controlled vehicle that starts with a speed of 1.0 m/s [forward] and then accelerates at 0.08 m/s2 [backward] for 4.0 s.
*Tuesday, June 3, 2014 at 5:23pm*

**physics**

The above graph represents the motion of two vehicles: A and B What is the acceleration of vehicle A during the first 5.0 s? Calculate the distance between vehicle A and B after 6.0 s? What is the instantaneous acceleration of vehicle A at the 10.0 s mark? What is the average ...
*Tuesday, June 3, 2014 at 5:02pm*

**Physics**

Calculate the maximum deceleration of a car that is heading down a 30.0° slope (one that makes an angle of 30° with the horizontal) under the following road conditions. You may assume that the weight of the car is evenly distributed on all four tires and that the ...
*Tuesday, June 3, 2014 at 4:49pm*

**physics**

An airplane requires 420 m of runway to take off from an airstrip. If the plane starts from rest and it takes 32 s to lift off, with what velocity does it leave the ground? What was the average acceleration of the plane?
*Tuesday, June 3, 2014 at 4:46pm*

**physics**

Jack is driving with a pail of water along a straight pathway at a steady 25 m/s when he passes Jill who is parked in her minivan waiting for him. When Jack is beside Jill, she begins accelerating at the rate of 4.0 × 10−3 m/s2 in the same direction that Jack is ...
*Tuesday, June 3, 2014 at 4:42pm*

**Physics**

am i correct? An electric oven has a resistance of 10.0Ω and a voltage of 220 V. How much current does it draw? A. 2.2 A B. 22 A <--- c. 220 A d. 2,200 A
*Tuesday, June 3, 2014 at 4:41pm*

**physics**

A lifeguard who can swim at 1.2 m/s in still water wants to reach a dock positioned perpendicularly directly across a 550 m wide river. If the current in the river is 0.80 m/s, how long will it take the lifeguard to reach the dock? If instead she had decided to swim in such a ...
*Tuesday, June 3, 2014 at 4:32pm*

**Physics**

Help me with this question, please How will the total voltage of a string of light bulbs in series change as you add more bulbs to the string? A. The total voltage will decrease B. The total voltage will stay the same C. The total voltage will increase d. You cannot predict ...
*Tuesday, June 3, 2014 at 4:13pm*

**physics **

A pilot is flying from City A to City B which is 300 km [NW]. If the plane will encounter a constant wind of 80 km/h from the north and the schedule insists that he complete his trip in 0.75 h, what air speed and heading should the plane have?
*Tuesday, June 3, 2014 at 4:02pm*

**physics**

A passenger on a train notices that a 2.00 kg mass is displaced 10.0° from the vertical as the train accelerates. (a) What is the acceleration of the train? (b) What would the acceleration be if the mass was 5.00 kg? c. What would angle have to be to indicate a horizontal ...
*Tuesday, June 3, 2014 at 3:17pm*

**Physics**

A 15.0 kΩ resistor is hooked up to a 45.0 V battery in a circuit with a switch. a.) What is the current flowing through the resistor? b.) What is the power dissipated by the resistor?
*Tuesday, June 3, 2014 at 3:16pm*

**Physics**

I know this is long but can someone just explain it to me? Please? Don't have to give the answer, I'm just confused :( 1. An experiment was devised to investigate the effects on the temperature of a cup of hot tea when lemon juice is added at different time intervals. ...
*Tuesday, June 3, 2014 at 2:21pm*

**Physics**

Consider the 52.0-kg mountain climber in the figure to the right. Find (a) the tension in the rope and (b) the force that the mountain climber must exert with her feet on the vertical rock face to remain stationary. Assume that the force is exerted parallel to her legs. Also, ...
*Tuesday, June 3, 2014 at 12:12pm*

**Physics**

Calculate the maximum deceleration of a car that is heading down a 30.0° slope (one that makes an angle of 30° with the horizontal) under the following road conditions. You may assume that the weight of the car is evenly distributed on all four tires and that the ...
*Tuesday, June 3, 2014 at 12:12pm*

**Physics**

A passenger on a train notices that a 2.00 kg mass is displaced 10.0° from the vertical as the train accelerates. (a) What is the acceleration of the train? (b) What would the acceleration be if the mass was 5.00 kg? c. What would angle have to be to indicate a horizontal ...
*Tuesday, June 3, 2014 at 12:11pm*

**Physics**

A 10.0N frictionless pulley is suspended from an overhead supported by a chain. two weights suspend off the pulley. One weight is 30.0N and the other is 20.0N. (a) What is the tension on the rope? (B) what is the acceleration of the weights? (c) what is the tension on the chain?
*Tuesday, June 3, 2014 at 12:09pm*

**Physics**

Q1:Find the phase and group velocities of the de Broglie waves of an electron whose kinetic energy is 500kev?
*Tuesday, June 3, 2014 at 8:48am*

**Physics**

A wind turbine has blades that sweep an area of 2000m2. It converts the power available in the wind to electrical power with an efficiency of 50%. What is the electrical power generated if the wind speed is 10ms–1? (The density of air is 1.3 kg m–3.)
*Tuesday, June 3, 2014 at 4:03am*

**Physics**

Q1: Find the frequency of revolution of the electron in the classical model of the hydrogen atom.In what region of the spectrum are electromagnetic waves of this frequency?? Q2:A beam of 13.o electrons is used to bombared gaseous hydrogen.What series of wavelengths will be ...
*Tuesday, June 3, 2014 at 3:36am*

**physics**

two identical copper spheres are separated by 1m in vacuum. how many electrons would have to be removed from one sphere and added to other sphere so that they attract each other with force of 0.9N
*Monday, June 2, 2014 at 11:44pm*

**Physics HELP ME PLEASE**

A 1250 kg car increases it's speed from 11 m/s to 27 m/s in 5.4 s. - What is the cars acceleration? - How much force is required?
*Monday, June 2, 2014 at 10:51pm*

**physics**

An astronaut on Triton throws a 0.142 kg baseball straight up with a velocity of 24 m/s. How high does the baseball go?
*Monday, June 2, 2014 at 10:40pm*

**physics**

A 280 N block rests on a 30° incline. (a) What is the normal force exerted by the incline on the block? (b) What (static) friction force is needed to prevent the block from sliding down the incline? (c) What is the minimum coefficient of static friction needed?
*Monday, June 2, 2014 at 9:07pm*

**Physics I NEED HELP BADLY**

An airplane traveling east at a speed of 270 km/h encounters a wind of 75 km/h what is the resulting speed of the plane if: - The wind is blowing east. - The wind is blowing west. - The wind is blowing north. ************* CLICK ON MY NAME TO SEE IF YOU CAN HELP ME WITH ANY ...
*Monday, June 2, 2014 at 6:37pm*

**Physics**

A 10.0N frictionless pulley is suspended from an overhead supported by a chain. two weights suspend off the pulley. One weight is 30.0N and the other is 20.0N. (a) What is the tension on the rope? (B) what is the acceleration of the weights? (c) what is the tension on the chain?
*Monday, June 2, 2014 at 6:29pm*

**physics**

A acorn falls from a tree and hits the ground with a speed of 10 m/s: - From what height did the acorn fall? - How long was the acorn in the air?
*Monday, June 2, 2014 at 6:29pm*

**Physics**

A car drives off a 20 m bridge at 35 m/s. Find the distance from the base of the bridge to when the car will land. (2 part question)
*Monday, June 2, 2014 at 6:27pm*

**Physics**

The velocity of a wave on a particular string is 21.8 m/s and the string is 3 meters long. What are the 3 lowest harmonic frequencies that with produce a standing wave?
*Monday, June 2, 2014 at 6:25pm*

**Physics**

20 wave crests pass a fisherman in one minute if the wave crests are 2.0 m apart find: Period Frequency Speed of waves
*Monday, June 2, 2014 at 6:22pm*

**physics**

two objects of equal mass are placed in a room. Object A is placed on the floor and object B is placed on a table top that is 3 meters of the ground. Which one has more potential energy and why?
*Monday, June 2, 2014 at 4:47pm*

**Physics **

A 50 g ball of clay traveling at speed v0 hits and sticks to a 1.0 kg block sitting at rest on a frictionless surface. A) What is the speed of the block after the collision? B) What percentage of the ball's initial energy is "lost"?
*Monday, June 2, 2014 at 3:25pm*

**Physics **

A) What is the kinetic energy of a 1200kg car traveling at a speed of 30 m/s (≈65mph)? B) From what height would the car have to be dropped to have this same amount of kinetic energy just before impact?
*Monday, June 2, 2014 at 3:24pm*

**physics**

A particle moves along the x-axis from an initial position xi to a final position xf. Of the following values of xi and xf, which results in a negative displacement? (a) xi = 6 m, xf = 4 m (b) xi = ?4 m, xf = ?2 m (c) xi = ?4 m, xf = 2 m (d) xi = 4 m, xf = 6 m (e) xi = ?4 m, ...
*Monday, June 2, 2014 at 3:06pm*

**physics**

You are going for a bike ride. You ride down a straight road at a speed of 9.0 mi/hr. Just as you pass the point which is 3.6 miles from your starting point, you develop a flat tire. You get off your bike and walk it to a bike shop 0.5 miles further down the road. The walk to ...
*Monday, June 2, 2014 at 2:12pm*

**Physics**

A 10.0 Ω resistor is hooked up in series with an 8.0 Ω resistor followed by a 27.0 Ω resistor. The circuit is powered by a 9.0 V battery -Calculate the equivalent resistance. -Calculate the voltage drop across each resistor in the circuit.
*Monday, June 2, 2014 at 1:43pm*

**physics**

What is the free-fall acceleration in a location where the period of a 2.87 m long pendulum is 3.4 s? Answer in units of m/s 2
*Monday, June 2, 2014 at 1:08pm*

**Physics**

A rock is thrown vertically up into the air. It reaches a maximum height 15m above point where it was released. What is its initial velocity? a) 17 m/s b) 26 m/s c) 14 m/s d) 20 m/s I know the answer is a) 17 m/s and I got it wrong thinking it was d) 20 m/s but I can't ...
*Monday, June 2, 2014 at 10:44am*

**physics**

a body of weight 10 n is kept on a smooth horizontal table.what is the force exerted on the table by the body
*Monday, June 2, 2014 at 1:19am*

**physics**

A senior citizen walks 275 m in 25 min going around a shopping mall. If she wants to increase her average speed by 25 % in walking a second lap, what would her travel time in minutes have to be?
*Sunday, June 1, 2014 at 11:36pm*

**physics**

A car is rounding a circular curve of radius r on a banked turn. As the drawing indicates, there are two forces acting on the car, its weight mg and the normal force FN exerted on it by the road. Which force, or force component, provides the centripetal force that keeps the ...
*Sunday, June 1, 2014 at 10:42pm*

**physics**

A car is rounding a circular curve of radius r on a banked turn. As the drawing indicates, there are two forces acting on the car, its weight mg and the normal force FN exerted on it by the road. Which force, or force component, provides the centripetal force that keeps the ...
*Sunday, June 1, 2014 at 10:39pm*

**Physics **

A) What is the kinetic energy of a 1200kg car traveling at a speed of 30 m/s (≈65mph)? B) From what height would the car have to be dropped to have this same amount of kinetic energy just before impact?
*Sunday, June 1, 2014 at 10:39pm*

**Physics**

A 1 kg hockey puck is sliding on the ice at 5m/s and stops on some dirt in 2 secs. I need to find the coefficient of kinetic friction. I found the acceleration being -2.5m/s^s (0-5m/s / 2s) Idk what to do next pleaseeee help
*Sunday, June 1, 2014 at 10:18pm*

**Physics (electricity and Magnetism)**

A long straight and thin wire has a charge Q per unit length. It is also carrying a current I. A point charge is moving with a velocity v parallel to the conductor, at a distance d from it. Find the velocity v, supposing a correct direction for the current and the current ...
*Sunday, June 1, 2014 at 8:37pm*

**physics**

A 68.0 kg ice skater moving to the right with a velocity of 2.55 m/s throws a 0.16 kg snowball to the right with a velocity of 27.5 m/s relative to the ground. (a) What is the velocity of the ice skater after throwing the snowball? Disregard the friction between the skates and...
*Sunday, June 1, 2014 at 6:22pm*

**physics**

A clerk moves a box of cans down an aisle by pulling on a strap attached to the box. The clerk pulls with a force of 173.0 N at an angle of 31° with the horizontal. The box has a mass of 40 kg, and the coefficient of kinetic friction between the box and the floor is 0.45. ...
*Sunday, June 1, 2014 at 1:07pm*

**Physics **

Two blocks A and B are connected by a light in extensible cord passing over a frictionless pulley. Block A starts from rest and moves up the smooth plane which is inclined at 30 degrees to the horizontal. Calculate at the moment that A has moved 4 m along the plane. (a) the ...
*Sunday, June 1, 2014 at 7:03am*

**Physics**

After undergoing through 90 degree compton scattering, the fraction of energy lost by photon is A) 10 % B) 50 % C) 20 % D) Zero E) None
*Sunday, June 1, 2014 at 6:28am*

**Physics**

A shell is fired from the ground with an initial speed of 1.54 ✕ 103 m/s at an initial angle of 52° to the horizontal. (a) Neglecting air resistance, find the shell's horizontal range. (b) Find the amount of time the shell is in motion.
*Saturday, May 31, 2014 at 11:31pm*

**physics**

Consider a pulse of laser light aimed at the Moon that bounces back to Earth. The distance between Earth and the Moon is 3.84 * 108 m. Show that the round-trip time for the light is 2.56 s.
*Saturday, May 31, 2014 at 9:27pm*

**physics**

A 3 kg object traveling 6m/s east has a perfectly elastic collilsion with a 4kg object traveling 8 m/s west After the sollision, the 3 kg object will travel 10 m/s west a. What was the total momentum before the collision? b. What is the total momentum of these objects after ...
*Saturday, May 31, 2014 at 6:26pm*

**Physics.**

A 500 g block lies on a horizontal tabletop. The coefficient of kinetic friction between the block and the surface is 0.25. The block is connected by a massless string to the second block with a mass of 300 g. The string passes over a light frictionless pulley as shown above. ...
*Saturday, May 31, 2014 at 4:34pm*

**Physics**

Please Help I have no idea how to approach this problem In a "Rotor-ride" at a carnival, people rotate in a vertical cylindrically walled "room." If the room radius was 5.7m , and the rotation frequency 0.35 revolutions per second when the floor drops out, ...
*Saturday, May 31, 2014 at 4:24pm*

**physics**

7. The speed of a man with and against the water currents in a river are 15km/h and 5km/h respectively. Find his speed in still water and the speed of the water currents.
*Saturday, May 31, 2014 at 6:13am*

**physics**

6. Two particles are moving with a constant speed v such that these are always at a constant distance d apart and their velocities are equal and opposite. After what time do these return to their original positions
*Saturday, May 31, 2014 at 5:52am*

**physics**

A stone is projected vertically to reach a maximum height 'h'. The ratio of kinetic energy to potential energy at a height 4h/5 is 1) 5:4 2) 4:5 3) 1:4 4) 4:1
*Saturday, May 31, 2014 at 2:04am*

**Physics**

A solid rubber ball has a diameter of 8.0 cm. It is released from rest with the top of the ball 80 cm above a horizontal surface. It falls vertically and then bounces back up so that the maximum height reached by the top of the ball is 45 cm, as shown. 80 60 40 20 If the ...
*Saturday, May 31, 2014 at 12:34am*

**Physics **

A 2.5-kg block is sliding along a rough horizontal surface and collides with a horizontal spring whose spring constant is 320 N/m. Unstretched, the spring is 20.0 cm long. The block causes the spring to compress to a length of 12.5 cm as the block temporarily comes to rest. ...
*Friday, May 30, 2014 at 10:23pm*

**Physics **

Two masses are connected by a string over an ideal pulley as shown. The coefficient of kinetic friction between m1 and the table surface is 𝜇. Find an expression for their common speed after the blocks have moved a distance L. You can assume that you know: m1, m2, L, ...
*Friday, May 30, 2014 at 10:23pm*

**Physics **

A box is pushed down an incline from point A to point B by a force F (and also under the influence of its weight). The distance from A to B, along the ramp, is 5.0 m. The force F is parallel to the incline, as shown, and has a magnitude of 2.0 N. The force of kinetic friction ...
*Friday, May 30, 2014 at 10:22pm*

**Physics **

A projectile is launched at an angle of 34.0o above the horizontal. The projectile has a mass of 1.50 kg and is given an initial speed of 20.0 m/s. a) What is the initial kinetic energy of the projectile? b) By how much does the gravitational potential energy of the projectile...
*Friday, May 30, 2014 at 10:22pm*

**Physics **

A pendulum consists of a swinging mass hanging from a massless string. The hanging mass is 2.0 kg and the string is 400.0 cm long. If the mass has a speed of 8.0 m/s when it passes the lowest point of its swing, a) what is the speed when the string makes an angle of 60.0o with...
*Friday, May 30, 2014 at 10:21pm*

**Physics **

A block of mass 12.0 kg is initially sitting at rest on a 30.0o incline. There is a spring mounted to the ramp with spring constant k = 13500 N/m. The block is released to slide down the incline and comes to a stop momentarily after the spring has been compressed a distance ...
*Friday, May 30, 2014 at 10:21pm*

**Physics**

A 2.50 kg fireworks shell is fired straight up from a mortar and reaches a height of 110. m. (a) Neglecting air resistance (a poor assumption, but we will make it for this example), calculate the shell’s velocity when it leaves the mortar. (b) The mortar itself is a tube ...
*Friday, May 30, 2014 at 7:02pm*

Pages: <<Prev | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | **12** | 13 | 14 | 15 | 16 | 17 | 18 | Next>>

Post a New Question | Current Questions