Review | Constants | Periodic TableNotice chge foet anation whes aking off and landingHopping is an efficient method caf locomotion for the kangaroo (see the figure above). When the kangaroo is in the air, the Earth-kangaroo system has a combination of gravitational potential energy and kinetic energy. When the kangaroo lands, its Achilles tendons and theattached muscies stretch-a form of elastic potential energy. This elastic potential energy is used along with additional muscle tension to launch the kangaroo off the ground for the next hop. In the red kangaroo, more than 50% of the total energy used during each hop isrecovered elastic potential energy. This is so efficient that the kangaroo's metabolic rate actually decreases slightly as its hopping speed increases from 8 km/h to 25 km/h.The horizontal and vertical force components exerted by a firm surface on a kangaroo's feet while it hops are shown in the figure. The vertical force Ns on K (the figure below) varies: when the kangaroo is nat touching the surface S, the force is zero; when it is pushing ofthe force is about three times the gravitational force that Earth exerts on the kangaroo. The surlace exerts a backward horizontal force (Fs on Ka) on the kangaroo's foot while it lands and a forward horizontal force as it pushes off for the next hop (the figure below).similar to what happens to a human foot when landing in front of the body and when pushing off for another step when behind the body. The force in the top point is Nmax = 1800 N and the mass of the kangaroo is m = 60 kg.(b)NVertical forcewhile contactingSufacePusng ferwandwhen takng ofN04t(s)wihen lining0204 Vertical forcewhile contactingsurfacePushing forwardwhen taking offt(s)Fsenks92Pushing backwhen landing0.4Fronkt(s)0.40.2Part AEstimate the vertical impulse due to the gravitational force exerted on the kangaroo by Earth during the short time interval while it takes off. Enter a positive value if the impulse is directed upwards and a negative value ifthe impulse is directed downward.Express your answer with the appropriate units.m2

Given, Mass of the kangaroo m = 60 Kg Landing time t =0.2/2 s

Estimate the vertical impulse due to the gravitational force exerted on the kangaroo by Earth during the short time interval while it takes off. Enter a positive value if the impulse is directed upwards and a negative value the impulse is directed downward.

Estimate the vertical impulse due to the gravitational force exerted on the kangaroo by Earth during the short time interval while it takes off. Enter a positive value if the impulse is directed upwards and a negative value the impulse is directed downward.

University Physics Volume 1

18th Edition

ISBN:9781938168277

Author:William Moebs, Samuel J. Ling, Jeff Sanny

Publisher:William Moebs, Samuel J. Ling, Jeff Sanny

Chapter7: Work And Kinetic Energy

Section: Chapter Questions

Problem 39P: A bungee cord is essentially a very long rubber band that can stretch up to four times its...

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