Question

Part B Constants A 1200 kg car is moving on the freeway at 69.0 mph. What is the magnitude of its kinetic energy in Sl units? K- 1 7430 Submit Previous Answers Request Answer Incorrect; Try Again; 5 attempts remaining PartC At what speed, in m/s, will the car's momentum be half of what it is in part A m/s Submit Request Answer MacBook Pro

Answer 1

v = 69 mph = 30. 846 m/s

a)

P = mv = 1200 * 30.846 = 37015.2 kgm/s

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b)

kE = 0.5 m v^2 = 0.5* 1200* 30.846^2

kE = 5.709*10^5 J

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c)

P' = mv / 2

m v' = m v/2

v' = 30.846 / 2= 15.423 m/s

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d)

kE' = kE/ 2

0.5 m v'^2 = 0.5* m v^2

v' = v / sqrt (2)

v' = 21.811 m/s

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