A particle moves under the influence of a conservative force. At point A the particle has a kinetic energy of 15 J ; at point B the particle is momentarily at rest, and the potential energy of the system is 30 J ; at point C the potential energy of the system is 6 J Part A What is the potential energy of the system when the particle is at point A? Express your answer using two significant figures. Πν ΑΣφ ? UA = J Submit Request Answer Part B What is the kinetic energy of the particle at point C? Express your answer using two significant figures. νη ΑΣφ Kc = J

A crate with mass m = 33.3 kg being pushed up an incline that makes an angle φ = 22.7 degrees with horizontal. The pushing force is horizontal, with magnitude P, and the coefficient of kinetic friction between the crate and the incline is μ = 0.358. Consider the work done on the crate as it moves a distance d = 5.32 m at constant speed. a. What is work done by the pushing force, in joules?  b. What is the work done by friction, in joules?  c. What is the work done by gravity, in joules?  d. What is the net work, in joules?

To stretch an ideal spring 8.00 cm from its unstretched length, 17.0 J of work must be done. Part A What is the force constant of this spring? Express your answer with the appropriate units. HA ? k Value Units %3D Submit Request Answer Part B What magnitude force is needed to stretch the spring 8.00 cm from its unstretched length? Express your answer with the appropriate units. HÀ ? F = Value Units Submit Request Answer

A particle moving along the x-axis is in a system Part B ▼ with potential energy U = 11/x J, where x is in m. What is the x-component of the force on the particle at x = 5 m? Express your answer to two significant figures and include the appropriate units. HẢ ? Fx = Value Units

You push a box up a ramp (friction between the box and the ramp is not negligible). Call the initial state when you begin to push the box. Call the final state after you have pushed the box up the ramp a distance of 0.5 m and it is moving with a speed of 2 m/s For which of the following systems does the energy remain constant?A. System: box + ramp + Earth + youB. System: boxC. System: box + ramp + EarthD. System: youE. System: box + rampF. None of the above.   Two cars are driving down the road. They notice that they are going to crash, so both drivers slam on the brakes. The cars skid, but still collide. The cars stick together and eventually slide to a stop. Call the initial state just before the drivers apply the brakes and the final state just after the collision had occurred. Treat this situation as realistically as possible. For which of the following systems does the energy remain constant?A. System: both carsB. System: both cars + the groundC. System: the second carD. System:…

A system in which only one particle can move has the potential energy shown in (Figure 1). Suppose U₁ = 80 J. Figure U (J) U₁ 0 1 2 T 3 4 5 y (m) 1 of 1 Part A What is the y-component of the force on the particle at y = 0.5 m ? Express your answer with the appropriate units. Fy = Submit Part B Fy = Submit μA Value Request Answer What is the y-component of the force on the particle at y = 4 m? Express your answer with the appropriate units. Provide Feedback μà Value Units Request Answer ? Units ?

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m. m A mass m, = 4.1 kg rests on a frictionless table and connected by a massless string over a massless pulley to another mass m, = 3 kg which hangs freely from the string. When released, the hanging mass falls a distance d = 0.83 m. 1) How much work is done by gravity on the two block system? 2) How much work is done by the normal force on m,? 3) What is the final speed of the two blocks? 4) How much work is done by tension on m,? 5) What is the tension in the string as the block falls? 6) The work done by tension on only m, is: O posítive zero negative

1. A roller-coaster car with a mass of 1200 kg starts at rest from a point 20 m above the ground. At point B, it is 9 m above the ground. [Express your answers in kilojoules (kJ).] a. What is the initial potential energy of the car? b. What is the potential energy at point B? c. If the initial kinetic energy was zero and the work done against friction between the starting point and point B is 40 000 J (40 kJ), what is the kinetic energy of the car at point B 2. The time required for one complete cycle of a mass oscillating at the end of a spring is 0.80 s. What is the frequency of oscillation?

The potential energy of an interaction is given by U(x)=ax², where a = +6.4 J/m². Initial speed of a 0.79-kg object in this system is 2.63 m/s at x = 0. A. How far does the object travel before it reaches a speed of v = 0? Express your answer with the appropriate units. B. Does your answer in the previous part depend on whether the object is traveling in the positive or negative  direction? Yes, the answer in the previous part is for the object traveling in the negative x� direction, the distance for the object traveling in the positive x� direction is greater than the obtained result. Yes, the answer in the previous part is for the object traveling in the positive x� direction, the distance for the object traveling in the negative x� direction is greater than the obtained result. No, it does not depend on whether the object is traveling in the positive or negative x� direction.