In a downhill ski race, your final velocity is not affected very much by getting a running start, because the initial kinetic energy is compared with the gain in gravitational potential energy on even small hillsHowever, you will finish the race much faster (which is more important ) To demonstrate this, find the final speed and the time taken for a skier who skies 82.5 m along a slope that is 19 degrees measured from horizontal , in the following situations (you may neglect friction ) A find the final speed in m/s lf the skier starting from rest B how long (in s) does it take for the skier to reach the bottom of this hill starting from rest C find the final speed in (m/s) of the skier with speed of 2.50 m/s D how long in (s) does it take for the skier to reach the bottom of this hill with a starting speed of 2.50 m/s

Use the principle of minimum potential energy developed in Section 3.10 to solve the bar problems shown in Figure P3-52. That is, plot the total potential energy for variations in the displacement of the free end of the bar to determine the minimum potential energy. Observe that the displacement that yields the minimum potential energy also yields the stable equilibrium position. Use displacement increments of O.002 in., beginning with x = -0.004. Let E = 30 x 106 psi and A = 2 in2 for the bars. 10,000 Ib 30 in. 10,000 lb 50 in. (b) Figure P3-52

(Figure 1) is the force-versus-position graph for a particle moving along the x-axis. Figure Fx (N) 4 2 0 -2 -4 1 2 3 -x (m) ▼ Part A Determine the work done on the particle during the interval 0-1 m. Express your answer with the appropriate units. Wo-1 = Units You have already submitted this answer. Enter a new answer. No credit lost. Try again. Submit Part B ΠΑ W1-2 = Submit Value Previous Answers Request Answer Determine the work done on the particle during the interval 1-2 m. Express your answer with the appropriate units. μA Value Units ? www Previous Answers Request Answer ? Units input for part B

How did you solve D? Wouldn't it's distance be different from that of Point 1 to Point 2 as would be Point 3 to Point 2 and shouldn't that effect the answer for work needed to be done?

(a) Check all of the following that are correct statements, where E stands for ymc². Read each statement very carefully to make sure that it is exactly correct. O At speeds close to the speed of light, kinetic energy is approximately equal to (1/2)mv². O The energy principle can be written AEsys Wsurr. %3D O The definition of work is W = |I. %3D O The definition K = E - mc² is valid even for speeds near the speed of light. O The definition of work is W = . O The definition of work is W = FxAx + F,AY + F;Az. %3D O The energy principle can be written Esys,f = Esys,i + Wsurr (b) An object with mass 120 kg moved in outer space. When it was at location its speed was 18 m/s. A single constant force N acted on the object while the object moved to location m. What is the speed of the object at this final location? final speed m/s %3D

At the Earth's surface, a projectile is launched straight up at a speed of 7.5 km/s. To what height will it rise? Ignore air resistance. 8.12e+06 X Your response differs from the correct answer by more than 10%. Double check your calculations. m

B9