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SECOND EXAM

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a. The Kinetic energy of the object decreases b. The kinetic energy of the object increases c. The applied force is changing d. The applied force is perpendicular to the

displacement e. Nothing. There is no such thing as negative

work

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26. Three balls having the same masses m are released simultaneously from the same elevation with speeds v but with different orientations: θ =90° , θ=45°, θ=30°. Neglecting air resistance, which of the following quantities will be the same for the three balls at the highest point of their motion?a. Total Mechanical energyb. Potential energyc. Kinetic energyd. momentume. speed

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A. B.

C. D.

E.

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For the next three problems: The angular position of an industrial fan changes with time as θ=π t2 rad/s2. The fan has a radius of 0.250 m. 36. What is the distance travelled by a point on the rim in 2.00 s?37. What is the average angular velocity between t1 = 0 s and t2 = 3 s?38. What is the instantaneous angular acceleration?

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41. Hayden (H) and Kho (K) are riding in a Flying Fiesta, EK stuff. Their positions relative to the axis of rotation are indicated in the figure. If for instance the swing ride moved at a constant angular velocity, which of the following is TRUE?a. θH < θK

b. ωH < ωK

c. vH < vK

d. atan,H < atan,K

e. Both C and D

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42. The moment of inertia of a solid sphere about an axis through its center is 2/5 MR2. The mass of the sphere is 5 kg and the diameter is 1 m. What is the moment of inertia about an axis tangent to the surface of the sphere?

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43. A wheel rotates counter clockwise on the x-y plane. A torque that causes the wheel to slow down is directed along the _____.