P2207_fall10_lecture10 - has a 4% grade. How can you keep...

Info iconThis preview shows pages 1–20. Sign up to view the full content.

View Full Document Right Arrow Icon
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 2
Today: Forces Solving force problems Why do tennis nets sag?
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
m F pull = mg =m*10m/s 2 a=? a=? A. 0 B. g C. >g D. insufficient information
Background image of page 4
m m m 3 1 2 T 1 / T 3 =? A. 1/3 B. 1/2 C. 1 D. 2 E. 3
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 6
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 8
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 10
• The Powder River Basin is one of the world’s largest coal producing region. 200 miles of coal trains leave the Powder River Basin every day, 365 days a year, bound for electricity generating plants. • Trains can be up to 2 miles long , and weigh 23,000 tons . Air drag from head winds can reduce an empty train’s speed on level ground from 50 to 20 mph.
Background image of page 11

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
m m m 3 1 2 F F In both cases, T 1 /T 3 = 3 If we add more masses, eventually rope 1 will break. a=0 No friction
Background image of page 12
• A steep railroad grade is 1.5% • (= 15 feet rise/1000 feet) • The steepest mainline track in the U.S.
Background image of page 13

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 14
Background image of page 15

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 16
Background image of page 17

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 18
Background image of page 19

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 20
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: has a 4% grade. How can you keep the couplers between cars from breaking? (Couplers on coal trains break routinely.) Front end of train: locomotive in remote control mode m 1 m 2 frictionless pulley a=? a=? A. 0 B. g C. m 1 g / (m 1 + m 2 ) D. m 2 g / (m 1 + m 2 ) E. (m 1- m 2 ) g / (m 1 + m 2 ) frictionless surface Why do Tennis Nets Sag? m T T T=? A. mg / 2 B. mg /sin( ) C. mg / cos( ) D. mg / 2 sin( ) E. mg / 2 cos( ) m T T T ? A. 0 B. mg / 2 C. mg D. 2mg E. As 0 (i.e., the ropes approach horizontal), T ? Other Applications sag of power lines power line and pole snapping by trees, ice plucking of guitar strings retrieving your car from a ditch...
View Full Document

This note was uploaded on 12/18/2011 for the course PHYS 2207 at Cornell University (Engineering School).

Page1 / 20

P2207_fall10_lecture10 - has a 4% grade. How can you keep...

This preview shows document pages 1 - 20. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online