Thursday

July 2, 2015

July 2, 2015

**physics**

A student drops an object from a fourth floor window. The velocity of the object is measured at 29.28 m/s 3.0 seconds later. What is the acceleration of the object?
*Wednesday, June 11, 2014 by Anonymous*

**Physics**

The Achilles tendon is attached to the rear of the foot as shown in (Figure 1) . A person elevates himself just barely off the floor on the "ball of one foot." Assume the person has a mass of 65kg and D is twice as long as d. Find the tension FT in the Achilles ...
*Tuesday, June 10, 2014 by George*

**Physics**

What is the maximum tension possible in a 1.15 mm diameter nylon tennis racquet string? The ultimate tensile strength for nylon is 5.00×10^8N/m2.
*Tuesday, June 10, 2014 by George*

**Physics**

Help please How do the dark lines of an atom's absorption spectrum relate to the bright lines of its emission spectrum? A. The bright lines are at the same energies as the dark lines. B. The dark lines are at higher energies than the bright lines. C. The bright lines are ...
*Tuesday, June 10, 2014 by Me and I*

**physics**

A flat circular mirror of radius 0.150 m is lying on the floor. Centered directly above the mirror , at a height of 0.750 m, is a small light source. Calculate the diameter of the bright circular spot formed on the 2.90 m high ceiling by the light reflected from the mirror.
*Tuesday, June 10, 2014 by Meghan*

**LA**

For questions 17–19, refer to the passage below: Albert Einstein, a world-famous mathematician was born in Bavaria in 1879. He acquired Swiss nationality in 1901 and he began working at the Swiss patent office the next year. Einstein was however also publishing papers in ...
*Tuesday, June 10, 2014 by dfca*

**Physics**

Determine the acceleration of a 1500 kg automobile that rolls down an incline of 30° from the horizontal if a coefficient of friction between the tires and the incline is 0.12
*Tuesday, June 10, 2014 by Corey Brown*

**Physics**

Calculate the tension in the cable connecting the two masses. Assume all surfaces are frictionless.
*Tuesday, June 10, 2014 by Corey Brown*

**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 10, 2014 by Corey Brown*

**Physics**

In the following diagram there is a coefficient of friction, μ, of 0.15 between the 5.0 kg mass and the surface. Calculate the tension in the cable connecting the two masses and the resulting acceleration.
*Tuesday, June 10, 2014 by Corey Brown*

**Physics**

A force of 3.0 N and 1.0 N act on a 6.0 kg mass as shown. What is the acceleration of the 6.0 kg mass
*Tuesday, June 10, 2014 by Corey Brown*

**Physics**

A 75.0-kg cross-country skier is climbing a 3.0o slope at a constant speed of 2.00 m/s and encounters air resistance of 25.0 N. Find his power output for work done against the gravitational force and air resistance. (b) What average force does he exert backward on the snow to ...
*Tuesday, June 10, 2014 by Anonymous*

**Physics**

(a) How high a hill can a car coast up (engine disengaged) if work done by friction is negligible and its initial speed is 110 km/h? (b) If, in actuality, a 750-kg car with an initial speed of 110 km/h is observed to coast up a hill to a height 22.0 m above its starting point...
*Tuesday, June 10, 2014 by Anonymous*

**Physics**

Am i Correct? 2.0 cm*.044T*/.10 s= 0.88 V Each side of a square loop of wire measures 2.0 cm. A magnetic field of 0.044 T perpendicular to the loop changes to zero in 0.10 s. What average emf is induced in the coil during this change? A. 1.8 V B. 0.088 V C. 0.88 V <-- D. 0....
*Tuesday, June 10, 2014 by Me and I*

**Physics**

I'm not really sure on this one... Am i correct? A maglev train requires which of the following? A. track and the train must have the different magnetic poles B. track and the train must have the same magnetic poles <--- C. magnetic poles must alternate between the ...
*Tuesday, June 10, 2014 by Me and I*

**Physics**

Am i correct? My work 0.10/0.20= .5 = 1/2 or is it the other way around? .20/.10? Suppose a magnetic field of 0.20 T is applied to the area within a circular loop of wire. The strength of the field is then changed to 0.10 T. By what factor is the magnetic flux changed? A. 2 B...
*Tuesday, June 10, 2014 by Me and I*

**Physics**

A spring with a force constant 0f 2.50 kN/M is set upright, and a wood platform of negligible weight is fastened to its upper end. A 2.50 kg mass is gently placed on the platform and released. How far does the spring compress? What is the final equilibrium position?
*Tuesday, June 10, 2014 by Anonymous*

**physics**

(a) How high a hill can a car coast up (engine disengaged) if work done by friction is negligible and its initial speed is 110 km/h? (b) If, in actuality, a 750-kg car with an initial speed of 110 km/h is observed to coast up a hill to a height 22.0 m above its starting point...
*Tuesday, June 10, 2014 by Anonymous*

**Physics**

Show that the x-component of the tension force Fc in terms of its magnitude Fc is given by -0.3420 Fc
*Tuesday, June 10, 2014 by Jane*

**physics!**

a 4.0 kg object has a velocity of 4.0 m/s headed east. an explosion causes it to break up into two smaller 2.0 kg objects. if one of the objects has a velocity of 3.0 m/s at an angle of 30 degrees east of north, what is the velocity of the other object after the explosion
*Tuesday, June 10, 2014 by Anonymous*

**physics**

An object of mass 5.0 kg is attached to a string of length 2.0 m and rotating in a horizontal circle with an angular velocity of 3.0 rad/s. What is the angular momentum of the object?
*Tuesday, June 10, 2014 by Anonymous*

**physics**

What is the angular velocity of the object shown below if it rotates about the point P in the center? The rotational kinetic energy of the object is 1.4 J, the mass M is 1.3 kg, and L is 0.50 m.
*Tuesday, June 10, 2014 by jessica*

**Physics**

A toy gun uses a spring with a force constant of 300. N/m to propel a 10.0-g steel ball. If the spring is compressed 7.00 cm and friction is negligible: (a) How much force is needed to compress the spring? (b) To what maximum height can the ball be shot? (c) At what angles ...
*Tuesday, June 10, 2014 by Anonymous*

**Physics**

A 75.0-kg cross-country skier is climbing a 3.0o slope at a constant speed of 2.00 m/s and encounters air resistance of 25.0 N. Find his power output for work done against the gravitational force and air resistance. (b) What average force does he exert backward on the snow to ...
*Tuesday, June 10, 2014 by Anonymous*

**Physics**

. (a) How high a hill can a car coast up (engine disengaged) if work done by friction is negligible and its initial speed is 110 km/h? (b) If, in actuality, a 750-kg car with an initial speed of 110 km/h is observed to coast up a hill to a height 22.0 m above its starting ...
*Tuesday, June 10, 2014 by Anonymous*

**Physics**

A spring with a force constant 0f 2.50 kN/M is set upright, and a wood platform of negligible weight is fastened to its upper end. A 2.50 kg mass is gently placed on the platform and released. How far does the spring compress? What is the final equilibrium position?
*Tuesday, June 10, 2014 by Anonymous*

**physics**

A man is playing tennis and a tennis ball (m=1.2 kg) approaches his tennis racket with a speed of 8.0 m/s. His racket is in contact with the ball for 2.0 ms and sends the ball flying in the opposite direction with a speed of 6.0 m/s. What is the magnitude of the average force ...
*Tuesday, June 10, 2014 by jessica*

**physics**

a vehicle is accelerating on a straight road. Its velocity at any instant is 30 km/hr, after 2 s, it is 33.6 km/hr and after further 2 s, it is 37.2 km/hr. Find the acceleration of vehicle in m/s^2
*Tuesday, June 10, 2014 by vicky*

**physics **

You have a box that contains 200 marbles. 99% of the marbles are green, the other 1% are white. How many green marbles would you have to remove from the box to reduce the percentage of green marbles to 98%?
*Tuesday, June 10, 2014 by Poop*

**physics**

A man in a circus shows jumps from a of 10m and is caught by the safety net which sags 2m due to his weight.calculate the average force exerted by the net on the man to stop his fall if the mass of the man is 60kg
*Tuesday, June 10, 2014 by khizar*

**physics**

A driver of a car travelling along a straight road with a speed of 72k.m./hour . Observes a sign board which gives the speed limit 54k.m./h.the signboard is 70m ahead when the driver applies break . Calculate the acceleration the car which will cause the car to pass the ...
*Tuesday, June 10, 2014 by pari*

**Physics**

The air pressure on Pikes Peak in Colorado is approximately 600 millibars. What is the relationship between air pressure at the top of Pikes Peak and at sea level, where air pressure is 1013 millibars?
*Tuesday, June 10, 2014 by mike *

**physics**

A skateboarder, with an initial speed of 4.2m/s , rolls virtually friction free down a straight incline of length 16m in 3.3 s.
*Tuesday, June 10, 2014 by Anonymous*

**physics**

A 370kg piano slides 2.9m down a 24∘ incline and is kept from accelerating by a man who is pushing back on it parallel to the incline. Ignore friction.
*Monday, June 9, 2014 by jim*

**physics**

The elastic potential energy of an object may be negative Select one: True False
*Monday, June 9, 2014 by jake*

**physics**

You shoot a 57 gram dart vertically upwards from a catapult with a spring constant of 379 N/m. The catapult is initially stretched from the equilibrium point by 30 cm. What is the height above the starting point reached by the dart? Ignore air resistance and give your answer ...
*Monday, June 9, 2014 by jake*

**physics**

An object of mass 1.6 kg is dropped from a height of 2.9 metres. It lands with a speed of 2.8 m/s. How much energy was lost due to air resistance? (Give your answer to 2 s.f., expressed as a magnitude)
*Monday, June 9, 2014 by allen*

**physics**

Calculate the magnitude of the force if a ball of mass 249.9 grams, and initial velocity +16.5 m/s is struck back on the same path with a final velocity of -22.0 m/s. Assume the contact time is 3.1 milliseconds. Use 2 s.f.
*Monday, June 9, 2014 by allen*

**physics**

An astronaut, mass 128.2 kg including spacesuit, pushes off from the International Space Station (mass 110 tons) with a speed of 1.2 m/s. What is the speed of the Space station in the opposite direction? Use 2 s f. for your answer
*Monday, June 9, 2014 by allen*

**Physics**

. A weightlifter lifts a 76.0 kg barbell 2.60 m 20 times in 1.50 minutes. What is his power output (a) in watts and (b) in hp?
*Monday, June 9, 2014 by Anonymous*

**Physics**

Calculate the maximum acceleration of a car that is heading up a 9.5° slope, assume that only half the weight of the car is supported by the two drive wheels and that the static coefficient of friction is 1.
*Monday, June 9, 2014 by Emma*

**Physics**

with this one i'm confused i'm not sure if it's b or d The current in a solenoid is changed from 1.1 A to 4.4 A. By what factor does the magnitude of the magnetic field inside the solenoid increase? 2 4 0.5 0.25 1.1/4.4= 0.25 0r 4.4/1.1= 4
*Monday, June 9, 2014 by Me and I*

**Physics**

Help please A wire carries a current of 5.2 A from east to west through a 6.0 m section of wire in the earth's magnetic field of 1 × 10^-5 T at a location where the magnetic field points south. What is the magnitude of the magnetic force acting on the wire? 3.1 &...
*Monday, June 9, 2014 by Me and I*

**Physics**

In a model yacht race on a river five identical yachts A,B,C,D,E are released at the same time from different points along the starting line. a)why should C win? b) as they approach the finishing line they all slow down. Why?
*Monday, June 9, 2014 by Bee*

**PHYSICS**

relation between time "t" and distance "x' is t=ax^2+bx where a and b are constant then acceleration is A / -2abv^2 b/ 2bv^3 C // -2av^3 D // 2av^2
*Monday, June 9, 2014 by AYESHA*

**physics**

Water is flowing through a horizontal pipe of varying cross section. At section 1,the diameter is 12cm at a pressure of 80000 Pa. At section 2, the pipe has a diameter of 6cm and the pressure is 60000 Pa. Find the speed of water through sections 1 and 2.
*Monday, June 9, 2014 by Haiano*

**physics**

In a spray can,the flow of air makes paint flow up the tube. As the air flows, it is blown away in droplets. A)as the air flows what happens to its speed and pressure? Why? B)why does the paint flow up the tube?
*Monday, June 9, 2014 by Haiano*

**physics**

In a model yacht race on a river five identical yachts A,B,C,D,E are released at the same time from different points along the starting line. a)why should C win? b) as they approach the finishing line they all slow down. Why?
*Monday, June 9, 2014 by Haiano*

**physics**

A child drops a ball from a height of 10 m. Assume its acceleration increases uniformly at the rate of 10m/s2. find the velocity with which the ball strikes the ground. Find the time taken to the ball reach the ground.
*Monday, June 9, 2014 by Anonymous*

**physics**

The mass of an atom can be determined by ionizing it and accelerating it through a known electric field followed by a known magnetic field. The ion’s circular path is then measured. Calculate the mass of a chlorine anion of charge 3.20 × 10−19 C if it follows ...
*Monday, June 9, 2014 by grey*

**physics**

Two straight and parallel wires of length 1.0 m carry a current — the first carries a current of 9.0 A while the other wire carries a current of 4.0 A. What distance must separate the two straight and parallel copper wires if the force between them is to be 6.0 × 10...
*Monday, June 9, 2014 by grey*

**physics**

A child drops a ball from a height of 10 m. Assume its acceleration increases uniformly at the rate of 10m/s2. find the velocity with which the ball strikes the ground. Find the time taken to the ball reach the ground.
*Monday, June 9, 2014 by Anonymous*

**physics**

Two straight conductors are 15 cm apart. If one conductor has a current of 12 A and the other has a current of 18 A, calculate the magnetic field at a point midway between the two conductors. The current in both conductors is flowing in the same direction.
*Monday, June 9, 2014 by grey*

**physics**

2.00 m long straight copper wire has a current of 8.0 A in it as it passes through a magnetic field. The magnitude of the force on the conductor is 2.00 N. The angle between the current and the magnetic field is 45°. What is the magnitude of the uniform magnetic field?
*Monday, June 9, 2014 by grey*

**physics**

a wire of resistance 5omega is bent in the form of a closed circle . what is the effective resistance between the two points at ends of any diameter of the circle?
*Monday, June 9, 2014 by jatin*

**physics**

The human body can survive an acceleration trauma incident (sudden stop) if the magnitude of the acceleration is less than 250 m/s2. If you are in an automobile accident with an initial speed of 136 km/h (85 mi/h) and you are stopped by an airbag that inflates from the ...
*Sunday, June 8, 2014 by Johanah*

**physics**

he drawing shows a steel ball rolling along a flat surface at constant velocity from point A to point B. A magnet exerts an attractive force on the ball only for the short time that passes as the ball rolls past point B. Which one of the following trajectories does the ball ...
*Sunday, June 8, 2014 by Sam*

**physics**

Two satellites are orbiting the Earth in stable circular orbits. Satellite A has a mass m and is located at a distance 2r from the center of the Earth. Satellite B has a mass 2m and is located at a distance r from the center of the Earth. Which one of the following statements ...
*Sunday, June 8, 2014 by Sam*

**physics**

A box containing supplies is vertically lowered at constant speed by a rope from a hovering helicopter. Consider the following forces that arise in this situation: force 1: the force of the earth pulling on the box force 2: the tension force acting on the box force 3: the ...
*Sunday, June 8, 2014 by Sam*

**physics**

The drawing shows a steel ball rolling along a flat surface at constant velocity from point A to point B. A magnet exerts an attractive force on the ball only for the short time that passes as the ball rolls past point B. Which one of the following trajectories does the ball ...
*Sunday, June 8, 2014 by Sam*

**Physics**

A model airplane is flying in a horizontal circle with a constant speed. The initial radius of the circle is R. The boy holding the cord to which the airplane is attached, then decides to increase the length of the cord so that the radius of the circle increases to 2R. The ...
*Sunday, June 8, 2014 by Sam*

**physics**

acceleration = 2,84 m.s Tension = 5,18 N
*Sunday, June 8, 2014 by Anonymous*

**physics**

The two blocks in the sketch are connected by a light cord over a frictionless pulley and are initially held in place. The block m1 has a mass of 2,00 kg and m2 has a mass of 3,00 kg. The inclined plane is frictionless and the coefficient of kinetic friction between block m1 ...
*Sunday, June 8, 2014 by Lysha*

**Physics**

Please Help! I am having difficulties grasping these concepts. Explain please! 1. How much heat energy is required to change 500 grams of water at 100 degrees Celsius to steam at 100 degrees Celsius? 2. How much energy is lost if 7kg of water is cooled from 46 degrees Celsius ...
*Sunday, June 8, 2014 by Tamai*

**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, ...
*Sunday, June 8, 2014 by Tami *

**physics**

A pendulum is suspended inside a car vertically suddenly the car is given a horizontal acceleration 'a'.The maximm angle through which the pendulum deflects is ?answer is 2tan inverse 'a'divided by g(acceleration due to gravity please solve this i have given ...
*Sunday, June 8, 2014 by zoha*

**Physics **

A 4.5kg box slides down a 4.1-m -high frictionless hill, starting from rest, across a 1.7-m -wide horizontal surface, then hits a horizontal spring with spring constant 490N/m . The other end of the spring is anchored against a wall. The ground under the spring is frictionless...
*Sunday, June 8, 2014 by Lena*

**Physics **

A horizontal spring with spring constant 110N/m is compressed 16cm and used to launch a 2.8kg box across a frictionless, horizontal surface. After the box travels some distance, the surface becomes rough. The coefficient of kinetic friction of the box on the surface is 0.15. ...
*Sunday, June 8, 2014 by Lena*

**Physics **

A system gains 473J of kinetic energy while losing 271J of potential energy. The thermal energy increases by 127J . Use an energy bar chart of this process to find the external work Wext.
*Sunday, June 8, 2014 by Tami *

**Physics**

Futurists project large space stations which would rotate so as to use centripetal acceleration to simulate gravity. The outer wall of the rotating space station would become a floor for the astronauts, and centripetal acceleration supplied by the floor would allow astronauts ...
*Sunday, June 8, 2014 by Anonymous*

**Physics**

Astrology, that unlikely and vague pseudoscience, makes much of the position of the planets at the moment of one’s birth. The only known force a planet exerts on objects on Earth is gravitational. (a) Calculate the gravitational force exerted on a 4.20 kg baby by the ...
*Sunday, June 8, 2014 by Anonymous*

**physics**

A geosynchronous Earth satellite is one that has an orbital period equal to the rotational period of the Earth. Such orbits are useful for communication and weather observation because the satellite remains above the same point on Earth, provided it orbits in the equatorial ...
*Sunday, June 8, 2014 by Anonymous*

**physics**

A body of mass 'M' starts sliding down on the inclined plane where the critical angle is 30 the coefficient of kinetic friction will be ?answer is square root 3 but how?i am not getting please help.
*Sunday, June 8, 2014 by zoha*

**Physics 20**

1. How much heat energy is required to change 500 grams of water at 100 degrees Celsius to steam at 100 degrees Celsius? 2. How much energy is lost if 7kg of water is cooled from 46 degrees Celsius to 2 degrees Celsius? 3. How much energy is gained when a 300g piece of ice at...
*Sunday, June 8, 2014 by Tamai*

**Physics-can someone please check this**

John is fired horizontally from a cannon with the speed of 24.5 m/s. In 3.0 seconds he strikes the earth down range. A net will be located on the ground to catch him. a) what is his initial position above the ground? b) What is the horizontal range to put the net? a)+ upward ...
*Sunday, June 8, 2014 by Presly*

**Physics**

A model airplane is flying in a horizontal circle with a constant speed. The initial radius of the circle is R. The boy holding the cord to which the airplane is attached, then decides to increase the length of the cord so that the radius of the circle increases to 2R. The ...
*Sunday, June 8, 2014 by Sam*

**Physics**

an 80kg man jumps off a 60m cliff, halfway to the ground, his GPE is 27,072J. What is his KE at the same moment?
*Sunday, June 8, 2014 by Mark*

**Physics**

A 1 kg mass is hung at the 0 mark of a meter stick and a 3 kg mass is hung at the 100 cm mark of the same meter stick. If the mass of the meter stick is 0.2 kg, at which of the following points of the meter stick could you balance the system on one finger? Select one: a. 38.9 ...
*Sunday, June 8, 2014 by Megan h.*

**physics**

A block of mass m = 0.605 kg is fastened to an unstrained horizontal spring whose spring constant is k = 67.5 N/m. The block is given a displacement of +0.120 m, where the + sign indicates that the displacement is along the +x axis, and then released from rest. (a) What is the...
*Sunday, June 8, 2014 by twill*

**physics**

You are traveling in a convertible with the top down. The car is moving at a constant velocity of 16.6 m/s, due east along flat ground. You throw a tomato straight upward at a speed of 9.85 m/s. How far has the car moved when you get a chance to catch the tomato?
*Sunday, June 8, 2014 by derick*

**Physics**

. A rock is thrown up into the air with an initial velocity of 15m/s up. What is the rock's velocity after 0.40 seconds?
*Sunday, June 8, 2014 by Bob*

**physics**

a homeowner wishes to drain her swimming pool by siphoning the water, whose depth is h, into a nearby gully a distance H below it,where H is much larger than h.she uses pipe of cross-sectional area a, and the pool has surface area A.how long does it take to empty the pool if h...
*Sunday, June 8, 2014 by khomotjo*

**Chemistry/physics**

The KE of a hydrogen atom's electron is 12.65 eV. Calculate the velocity of the electron? Known: KE=mv^2
*Sunday, June 8, 2014 by Fernandez*

**Physics**

A block takes 3 times as long to slide down an inclined plane that makes an angle of 30 degrees as it does to fall freely through the same vertical distance. Determine the coefficient of friction? I have no idea where to start on this. :(
*Sunday, June 8, 2014 by Haff*

**physics**

What is the pressure due to a man weighing 80 kg standing on his feet? given area of his feet is 160sq.cm take g=10m/s^2
*Sunday, June 8, 2014 by Vidhya*

**physics**

Gradually increase the angle of the incline, but keep the angle low enough that the block does not slide. Select all the phrases below that would make the following statement true: For this situation, as the angle is increased the maximum possible value of the force of static ...
*Sunday, June 8, 2014 by Sam*

**physics**

Joe pushes horizontally on a heavy box across a rough surface at constant speed. Which one of the following statements concerning this situation is false? If Joe stops pushing on the box, the box will stop sliding eventually. If Joe doubles his force on the box, the speed of ...
*Sunday, June 8, 2014 by Sam*

**Physics**

A ball is sitting in a child's wagon and a child is holding the wagon's handle. The ball then rolls to the back of the wagon without anyone touching the ball directly. Which of the following statements according to Newton's first law of motion could describe the ...
*Sunday, June 8, 2014 by Sam*

**Physics**

A train on a mountain railway is carrying 200 people of average mass 70kg up a slope at an angle of 30° to the horizontal and at a speed of 6.0 m s–1. The train itself has a mass of 80 000 kg. The percentage of the power from the engine which is used to raise the ...
*Sunday, June 8, 2014 by Me*

**physics**

prove that for finite length current element ?H = I/2πr(sinα2 - sinα1)aφ
*Sunday, June 8, 2014 by Anonymous*

**physics**

Three identical point charges A, B, and C are located in the shape of an equilateral triangle with sides of length 15 cm. What is the net force on B if each charge has a magnitude of −5.0 × 10−3 C?
*Sunday, June 8, 2014 by grey*

**physics**

Energy & Momentum Calculations Assessment Answer the following questions. 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 ...
*Sunday, June 8, 2014 by grey*

**Physics**

Can someone explain the magnitude and direction of the acceleration of a ball moving upward, downward,and at the highest point? a=g
*Sunday, June 8, 2014 by Tasha*

**physics**

Calculate the mass of the star using the fact that the period of the planet is 3.07 × 107 s and its distance from the star is 1.26×1011 m. Answer in units of kg
*Saturday, June 7, 2014 by anon turtle*

**Physics**

June stands on the roof of the house which is 22.8 m high and she throws the ball at an initial speed of 4.90 m/s downward at Ben who is 1.80m tall. a) With what speed does she hit her target's head and b) how much time was it in the air? Displacement= 21 m. -Place ...
*Saturday, June 7, 2014 by Luis*

**physics**

Which one of these statements concerning elastic collisions is FALSE? Select one: a. The two objects remain together after collision b. The kinetic energy is conserved c. The momentum is conserved
*Saturday, June 7, 2014 by jake*

**physics**

An electron reaches a speed of 3.0 × 107 m/s when released beside the negative plate within a parallel plate accelerator with a gap of 15.0 cm. If the mass of an electron is 9.11 × 10−31 kg, what is the potential difference between the plates?
*Saturday, June 7, 2014 by grey*

**physics**

You shoot a 57 gram dart vertically upwards from a catapult with a spring constant of 379 N/m. The catapult is initially stretched from the equilibrium point by 30 cm. What is the height above the starting point reached by the dart? Ignore air resistance and give your answer ...
*Saturday, June 7, 2014 by jake*

**physics**

Which one of these statements regarding non-conservative forces is FALSE? Select one: a. A non-conservative force cannot have a potential energy defined for it. b. The work done by a non-conservative force may be either positive or negative depending on the direction of motion...
*Saturday, June 7, 2014 by jake*

**college physics**

A horizontal spring with a spring constant k = 322 N/m is uncompressed from a length of 1.4 cm back to its unstretched length. Calculate the change in potential energy in Joules to 2 s.f.
*Saturday, June 7, 2014 by wes*