Unformatted text preview: r su ddenly came to a stop. Why? a. gravity made the driver’s head move forward b. the force of the collision pushed the driver’s head into the steering wheel c. the steering wheel was pushed back into the driver’s head d. the driver’s head has inertia Question 17 – Plumbers sometimes fit a length of PVC p ipe onto the end of a pipe wrench. Why? a. to reduce the torque on fragile fittings b. to increase the friction between their hand and th e wrench handle c. to increase the torque they can apply d. to reach high and out of the way plumbing PHYS115 ‐ Fall 2012 6 Test 1 ‐ October 2012 Question 18 – A 80 kg father and his 20 kg daughter dec ide to enjoy balancing on a seesaw. The seesaw is a uniform board 4 m long and pivoted exactly at its center. If girl sits at the seesaw’s y
end (2 m from the center), how far from the center on th e other side should the father sit? a. farther out than the board will allow
b. 0.5 m c. 0.4 m d. 1.5 m Question 19 – The Earth spins from west to east on its ax xis.
It is slowing down in its rotation due to friction with the air. spinning North Pole In which direction is the frictional torque vector? d . a. South Pole to North Pole b. North Pole to South Pole c. c. counterclockwise along the equator (see diagram ) d. clockwise along the equator (see diagra...
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