Frictionless Definition and 468 Threads

Homework Statement Two masses are connected by means of a string which passes over a light frictionless pulley. The coefficient of kinetic friction between the 9kg mass and the table is 0.25. The applied force on the 9kg mass is unknown and the acceleration of the unknown mass, m, is 1m.s^2...

A 100 kg box is pulled up an inclined plane by a massless, frictionless winch to which it is attached by a massless rope. The plane makes an angle of 45° with respect to the horizontal. The coefficient of friction between the box and the plane is μ = 0.25 (with μs = μk). The winch has a radius...

Homework Statement A hand pushes a 3 kg block along a table from point A to point C as shown in the figure below. The table has been prepared so that the left half of the table (from A to B) is frictionless. The right half (from B to C) has a non-zero coefficient of friction equal to u. The...

http://img530.imageshack.us/my.php?image=hrwc5f51km4.gif A 1.7 kg mass, m2, on a 30.5° incline is connected to a 6.4 kg mass, m1, on a horizontal surface. The surfaces and the pulley are frictionless. If F = 13.3 N, what is the magnitude of the tension in the connecting cord? I've tried solving...

800 kg roller coaster is initially at the top of a rise, at point A. It then moves 125 ft (38.1 m), at an angle of 40.0° below the horizontal, to a lower point, B. (a) Choose point B to be the zero level for gravitational potential energy. Find the potential energy of the roller coaster-Earth...

Homework Statement A bug slides back and forth in a bowl 11cm deep, the bowl is frictionless except a 1.5cm patch at the *flat* bottom coefficient of friction = .61 Homework Equations W = f*d r= 11cm \mu=.61 stickypatch=1.5cm The Attempt at a Solution i can get the first part (its...

Homework Statement A shipping container is hauled up a roller ramp that is effectively frictionless at a constant speed of 2.10 m/s by a 2250 N force that is parallel to the ramp. If the ramp is at a 24.7° incline, what is the container's mass? Homework Equations Fx = mg sin(theta) F =...

I have tried to get this problem many different ways but still don't get it. A 1.00 kg aluminum block and a 8.00 kg copper block are connected by a light string over a frictionless pulley. The two blocks are allowed to move on a fixed steel block wedge (of angle θ = 40.0°) as shown in Figure...

Homework Statement A man pushes a create which weighs 75 N upward along a frictionless slope that makes an angle of 30° with the horizontal. The force he exerts is parallel to the slope. If the speed of the crate increases at a rate of 0.5m/s^2, then the work done by the man while moving the...

1. a 1400 kg car with a cross section of 1.8m wide and 1.46m high slides across a frictionless surface at 19 m/s. The question is how long does it take (in seconds) to get to 13 m/s? the 2nd part is how long it does it take to get to 10 m/s? 2. D = .5(A)v^2 where A is the area of cross...

There are actually 2 questions that i have Homework Statement First is a frictionless pulley with zero mass is attached to the ceiling, in a gravity field of 9.80 m/s2. Mass M2=0.250 kg is being accelerated downward with a=1.40m/s2. calculate the mass m1. Second is A small steel ball...

Homework Statement A particle initially sits on top of a large smooth sphere of radius R. The particle begins to slide down the sphere without friction. At what angle . does the particle lose contact with the sphere? Homework Equations g=9.8m/s2 perhaps? (Is this dependent on the...

Homework Statement This is straight from the book. A small block of mass m rests on the sloping side of a triangular block of mass M which itself rests on a horizontal table as shown in Fig. 4-50. Assuming all surfaces are frictionless, determine the force F that must be applied to M so...

Homework Statement Sam (65 kg) takes off (from rest) up a 50 m high, 10° frictionless slope on his jet-powered skis. The skis have a thrust of 260 N. He keeps his skis tilted at 10° after becoming airborne, as shown in Figure P6.43. (Figure attachment not working- it's basically just drawing...

Homework Statement "A crate of mass 50 kg is pushed across a frictionless horizontal floor with a force of 100N directed 23.5 degrees below the horizontal. The magnitude of the normal force of the floor on the crate is:" Homework Equations F = ma? Not sure what else would apply...

A 1.6 -long, 550 rope pulls a 9.0 block of ice across a horizontal, frictionless surface. The block accelerates at 1.0 . 1) How much force pulls forward on the block of ice? 2) How much force pulls forward on the rope?

Block on frictionless floor! A 3.70 kg block located on a horizontal frictionless floor is pulled by a cord that exerts a force F=13.0 N at an angle q= 25.0° above the horizontal, as shown. What is the speed of the block 3.70 seconds after it starts moving? I have drawn a picture...

Homework Statement A rope of mass M and length L lies on a frictionless table, with a short portion L0 hanging through a hole. Initially the rope is at rest. Evaluate A and B so that the initial conditions are satisfied. The Attempt at a Solution Ok, so I understand the problem and...

1. What is the acceleration of a skateboard down a ramp inclined at 19.5 degrees to the horizontal? 3.271 is the answer. 2. I know g Sin\vartheta is the equation to get it, but I don't get why it isn't g divided by Sin\vartheta 3. In my head I thought the picture was like...

Homework Statement A 100 kg man stands on the left end of a 100 kg board 2 meters long which sits on a frictionless surface as shown. Where will the left end of the board come to rest if the man walks to the right end of the board and stops? http://pics-hosting.com/files/pexpnaxozyl1o2qins.jpg...

Homework Statement https://www.physicsforums.com/attachment.php?attachmentid=14568&stc=1&d=1214858251" There is no friction between the masses. The first part of the question is to find the force F so that m2 will be in rest (in respect to m3). The second part is, what are the...

A 3kg block is released from rest at the top of a frictionless ramp 1.5m long. The acceleration of the blick is measured to be 3.8m/s/s. What is the angle x of the ramp? all answers in degrees a)x= 12.1 b)x=16.3 c)x=22.8 d)x=25.2 e)x=37.4

..and he brings in his arms to decrease his moment of inertia in order to increase his angular velocity, that means the rotational kinetic energy increases. But that means there's a change in rotational kinetic energy, right? But wouldn't there be no external forces acting on him (assuming no...

Homework Statement A frictionless pulley has the shape of a uniform sold disk of mass 2.5 kg and radius .2m. A 1.5kg stone is attached to a very light wire that is wrapped around the rim of the pulley, and the system is released from rest. (a) How far must the stone fall so that the pulley has...

True or False: As a stone slides down a frictionless ice covered hill its mechanical energy is concerved but its momentum is not. False- if mechanical energy is concerved so is momentum right??

I'm stuck on this problem. A sledge of mass 120 kg is at rest on a horizontal icy surface. A man of mass 70 kg stands at one end of the sledge so the initially the distance from the man to the shore is 20 m. The man now walks 3 m relative to the sledge, towards the shore. The he stops...

Homework Statement A 20.0 kg block is connected to a 30.0 kg block by a string that passes over a light, frictionless pulley. The 30.0 kg block is connected to a spring that has negligible mass and a force constant of 240 N/m, as shown in the figure below. The spring is unstretched when the...

Is there anything that stops the formation of a perfectly frictionless surface? There isn't even enough to type to make a second sentence here.

The weights of the objects are 200 N and 300 N. The pulleys are essentially frictionless and massless. P1 has a stationary axle but P2 is free to move up and down. Find the tensions FT1 and FT2 and the acceleration of each body. Diagram I made in paint attached. Now my problem is not that...

[SOLVED] Please help: A box on a frictionless plane, find the power based on work and Homework Statement A box of mass M = 7.68 kg is at rest at the bottom of a frictionless inclined plane. The box is attached to a string that pulls with a constant tension T = 113 N. Write the general...

1. A 1.5 kg rock is being twirled in a circle on a frictionless surface using a horizontal rope. The radius of the circle is 2.00m and the rope makes 100 revolutions in 1.00 minutes. What is the tension in the rope? This problem has totally confused me. I don't even know what equation to...

three blocks on a frictionless 45° ramp held together by massless ropes top block's mass, m1=1.00 kg. middle block's mass, m2=2.00 kg bottom block's mass, m3=3.00 kg. 1. the force 'FE' is exerted on block one and is just enough to hold all the blocks in place find FE and the tensions of the...

a block is pushed up a frictionless 30 incline by an applied force the force F=50 N and the mass = 3 kg whats the magnitude of the resulting acceleration of the block ? sol: -Fcos30=ma mg+Fsin30=ma right answer for a=9.4

Homework Statement Consider the frictionless roller coaster shown. (Diagram attached) If a 12000 kg car starts at rest from Point A, calculate: a) the total energy of the system b) the speed of the car at point B c) the force that must be applied to bring it to a stop at point E d) the work...

Homework Statement A 4kg object is palced on a table with a coefficient of friction of 0.2, and attached to a rope. This rope is run through a frictionless pulley, and attached to an 8kg weight. What is the tension in the rope? Homework Equations F=ma F of friction = (coefficient of...

We have a spring-mass system which oscillates in one dimension on a frictionless horizontal surface. We act an external force on the mass. F=kχo sin(ωt). Let x=Asin(ωt+φ),A>0 and ωο is the natural frequency of the system. a) What is the phase of the motion of the mass relatively to the phase of...

A cue ball (mass=0.165kg) is at rest on a frictionless pool table. The ball is hit dead center by a pool stick, which applies an impulse of +1.50Ns (Newton-seconds) to the ball. The ball the slides along the table and makes an elastic head-on collision with a second ball of equal mass that is...

Homework Statement It's been a great day of new, frictionless snow. Julie starts at the top of the 60 ^\circ slope shown in the figure. View Figure At the bottom, a circular arc carries her through a 90 ^\circ turn, and she then launches off a 3.0-m-high ramp. How far is her touchdown...

Homework Statement A wedge with mass rests on a frictionless horizontal table top. A block with mass is placed on the wedge. There is no friction between the block and the wedge. The system is released from rest. Homework Equations (-gm)/((M+m)tan(alpha)+(M/tan(alpha))) The...

a Skier of mass 60 kg pushes off the top of a frictionless hill with an initial speed of 5.0 m/s. How fast will she be moving after dropping 20m in elevation? i don't know how to compute this without the angle

Homework Statement Well i have a tiny question here a 2 kg mass starts at rest and slides down a 10 m high, 15 m long frictionless ramp. At the bottom of the ramp it reaches a flat surface where it hits and sticks to a stationary 3 kg mass . Find the final speed of the masses after...

Hey all. My professor gave us this question in class the other day but I'm having a hell of a time reasoning out how the answer can be true. Firstly, the problem: There's a bucket on wheels moving at a constant velocity on a frictionless surface. It's raining out so the bucket is gaining...

[SOLVED] help- speed Mass m_1 on the frictionless table of the figure is connected by a string through a hole in the table to a hanging mass m_2. With what speed must m_1 rotate in a circle of radius r if m_2 is to remain hanging at rest? i know i am suppose to show what i have done...

Homework Statement A 250 g block is resting on a frictionless horizontal surface. The block is attached to a spring. The mass-spring system is compressed by a 2.5 N force and then released from rest. (a) The resulting oscillation has a 1.0 s period. What is the spring constant? (b) What is...

Homework Statement A small cylindrical disk hits a more massive square block directly head on. Both objects slide without friction on a smooth ice surface. The block is pushed forward and the disk bounces back. Which statement is true? a) The block pushes the disk. b) The disk exerts a...

A massive steel cable drags a 20 kg block across a horizontal, frictionless surface. A 100 N force applied to the cable causes the block to reach a speed of 4.0 m/s in a distance of 2.0 m. What is the mass of the cable? I hate to ask you folks for a lot of help. But I have no idea...

Homework Statement A bug lands on top of the frictionless, spherical head of a bald man. It begins to slide down his head. Show that the bug leaves the head when it has dropped a vertical distance 1/3 the radius of the head. Homework Equations Not sure. Maybe: E_f - E_i = 0...

Homework Statement A block of mass m = 2.00 kg is released from rest at h = 0.500 m from the surface of a table, at the top of a θ = 35.0° incline as shown below. The frictionless incline is fixed on a table of height H = 2.00 m. How much time has elapsed between when the block is...

Homework Statement Two boxes with different masses M1 = 1.3 kg and M2 = 2.2 kg are tied together on a frictionless ramp surface which makes an angle = 29° with the horizontal (see the figure below). (the figure is essentially two boxes tied together by a rope and then another rope tying the...

Homework Statement A block of ice slides down a frictionless ramp at theta = 60 degrees while an ice worker pulls on the block (via a rope) with a constant force of 50.0 N. The block slides a distance d = 0.8m along the ramp and its kinetic energy increases by 128 J. (a) Calculate the work...