Thanks to recent satellite data, we know that the North American continent is drifting westward at a speed of about 1cm/yr. We can assume that the solid part of a continent is about 50 kilometers thick. Estimate the kinetic energy that the continental US has as a result of this motion.

Explorers in the jungle find an ancient monument in the shape of a large isosceles triangle as shown in the figure below. The monument is made from tens of thousands of small stone blocks of density 3 293 kg/m. The monument is 14.0 m high and 64.0 m wide at its base and is everywhere 2.50 m thick from front to back. Before the monument was built many years ago, all the stone blocks lay on the ground. How much work did laborers do on the blocks to put them in position while building the entire monument? Note: The gravitational potential energy of an object-Earth system is given by U, = Mgy CM, where M is the total mass of the object and yCM is the elevation of its center of mass above the chosen reference level.

A 150-g particle on the inside of a smooth hemispherical bowl of radius R 35.0 cm (see the figure below) is released from point A at rest. Its speed at B is 1,10 m/s. (a) What is its kinetic esergy at B? T h (b) How much mechanical energy is lost as a result of friction as the particle goes from A to B2 (c) Is it possible to determine u from these results in a simple manner? O Yes O No Explain. ..

A roller-coaster car of mass 1.50 × 103 kg is initially at the top of a rise at point Ⓐ. It then moves 35.0 m at an angle of 50.0° below the horizontal to a lower point Ⓑ. (a) Find both the potential energy of the system when the car is at points Ⓐ and Ⓑ and the change in potential energy as the car moves from point Ⓐ to point Ⓑ, assuming y = 0 at point Ⓑ. (b) Repeat part (a), this time choosing y = 0 at point Ⓒ, which is another 15.0 m down the same slope from point Ⓑ.

A 71.1-kg boy is surfing and catches a wave which gives him an initial speed of 1.60 m/s. He then drops through a height of 1.59 m, and ends with a speed of 8.51 m/s. How much nonconservative work (in kJ) was done on the boy?

Jumping spiders jump by altering the pressure of their body fluid within them, thereby causing their legs to suddenly extend. Suppose a jumping spider of mass 16.5 mg springs off a leaf at an angle of 69.8 degrees with respect to the horizontal. While the spider is pushing off from the leaf, the leaf together with a prevailing breeze, exert on it an average force of 1.8 N in the direction of the jump. If this force does 0.78 mJ of work on the spider, by what length (in mm) do the spider's legs extend while it is taking off? Assume the spider's legs extended in the vertical direction and neglect any difference between the length of the leg extension

A child of mass m = 16 kg slides down a slide of height h = 2.7 m without friction. Let gravitational potential energy be zero at ground level. a)Write an expression for the child's total mechanical energy, E, at the top of the slide, in terms of the variables in the problem and the acceleration due to gravity g.  b)Calculate the change in the child's potential energy, ΔU in joules, from the top to the bottom of the slide at ground level (i.e. ΔU = Uground - Utop).  c)What is the child's final speed, vf in m/s?

Ricky moves a wagon a distance of 36 meters by pulling the handle with a force of 120 Newtons. If 2200 Joules of work is done on the wagon, at what is the angle between the wagon handle and the horizontal? Foull A 1° B 31° C 27° 59° O O O

P2.7 By evaluating the integral w = - S Pext dV, calculate the work done in each of the cycles shown below in units of Joules. (a) 1 2 3 4 V (L) P (bar) N (c) 1 (b) 3 2 V (L) 4 1 1 1 2 3 V (L) 4

Please answer within 90 minutes.