A box of mass 4.0 kg hangs by a cable from the ceiling of an elevator. The elevator is moving up at a steady speed of 5.0 m/s for 8.0 m. Use g = 10 m/s2. Consider the system is the box and the Earth. When apply the following energy principle, considering the system is box+earth, which of the energy term is positive? Select all apply. ΔK + ΔUg + ΔUsp + ΔEth + ΔEch = Wext

A-C please!

The Elf on the Shelf has mass 0.500 kg and is sitting on a shelf some height y above the ground.The gravitational potential energy is 49.0 J? The Elf is bumped and falls off the shelf. How fast will the Elf be moving just before it strikes the ground?

As shown in the figure below, three blocks with masses m₁ = 4.8 kg, m2 = 14 kg, and m3 = 18 kg, respectively, are attached by strings over frictionless pulleys. 1711 m2 ms The horizontal surface exerts a 32 N force of friction on m2. If the system is released from rest, use energy concepts to find the speed (in m/s) of m3 after it moves down 3.0 m. m/s

Situation 02. A crate has a mass of 120kg and the coefficient of static and kinetic friction is 0.60 and 0.50, respectively. The crate starts from rest and the motor exerts a tension T= 1220 + 200t (N). If the elevation of the dock is 30 degrees from the horizontal, a. What is the velocity of the crate after 1sec? b. Compute the power transmitted after 1sec.

A box of mass 4.0 kg hangs by a cable from the ceiling of an elevator. The elevator is moving up at a steady speed of 5.0 m/s for 8.0 m. Use g = 10 m/s2. Consider the system is the box and the Earth. When apply the following energy principle, considering the system is box+earth, which of the energy term is positive? Select all apply. ΔK + ΔUg + ΔUsp + ΔEth + ΔEch = Wext Answer choice     ΔK     ΔUg      ΔUsp     ΔEth      ΔEch     Wext

Suppose you are biking at a constant speed up a road inclined at 5° above the horizontal. You need to bike up this hill for 200 m in 2 minutes or less. There is an average drag force of 25 N as well. Calculate the minimum amount of power in hp your body must provide in order to make it up this hill in time. Assume 80 kg total mass of yourself and bike and 25% energy efficiency in your body. Define a system and draw energy state diagrams as part of your solution. Draw any necessary FBDs for forces. B

An object whose mass is 10 lb is projected straight upward from the surface of the earth and reaches a height of 100 ft when its velocity reaches zero. The only force acting on the object is the force of gravity. The acceleration of gravity is g = 32.2 ft/s². Determine the initial kinetic energy of the object, in ft·lbf, and the initial velocity of the object, in ft/s.

A 50-N crate initially has kinetic energy 10.0 J at the top of a rough incline of 60 degrees.   A constant horizontal force is applied to the crate as it moves down the incline in dynamic equilibrium.    Is the work from the following forces positive, negative or zero?   Explain your reasoning. Normal, Weight, Applied and Friction Is the net work positive, negative or zero?  Explain your reasoning. How do your answers for (a) and (b) change if the crate is displace up the incline instead?