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.

College Physics

11th Edition

ISBN:9781305952300

Author:Raymond A. Serway, Chris Vuille

Publisher:Raymond A. Serway, Chris Vuille

Chapter1: Units, Trigonometry. And Vectors

Section: Chapter Questions

Problem 1CQ: Estimate the order of magnitude of the length, in meters, of each of the following; (a) a mouse, (b)...

See similar textbooks

Similar questions

A baseball of mass 0.145 kg is pitched at a speed of 39.0 m/s, the ball is hit back towards the pitcher with a speed of 52.0 m/s. I) What is the magnitude of the impulse delivered by the bat to the baseball? (a) 13.2 kg m s (b) 1.89 kg m s (c) 13.0 kg m s (d) 943 kg m s II) Find the magnitude of the average force, in kN, exerted by the bat on the ball if the two are in contact for 2.00x10° s.
irai, a 50 kg figure skater, lands on the ice her feet after landing the triple axel and immediately jumps up again to perform a double toe-loop. The instant before her skates first touch the ice after the triple axel, her vertical velocity is 3 m/s downward. Her velocity is 2 m/s upward when her skates leave the ice for the second jump, 0.8 s later. (a) What is the vertical impulse exerted on Mirai during the 0.8 s she is in contact with the ice between the two jumps? (b) What is the average net vertical force exerted on Mirai during this 0.8 s? (c) What is the average reaction force exerted upward by the ice on Mirai during the 0.8 s?
A car of mass m = 1.01 tonnes travelling northward enters an intersection at vo = 60 km/h. The car is struck by a truck entering the intersection from its left. The car is deflected by an angle 3 = 30° and recoils from the collision at a speed v = 61.2 km/h, as shown in the figure, Z4 Truck Car What is the magnitude of the impulse of the force of the truck onto the car during the collision? Number Units What is the direction of the impulse with respect to east (with anti-clockwise positive)? Number Units If the duration of the collision is 0.26 s, what is the magnitude of the average force exerted by truck on car? Number Units
Particle 1 of mass 230 g and speed 3.50 m/s undergoes a one-dimensional collision with stationary particle 2 of mass 400 g. (a) What is the magnitude of the impulse on particle 1 if the collision is elastic? kg. m/s (b) What is the magnitude of the impulse on particle 1 if the collision is completely inelastic? kg m/s | Submit Answer
(a) If the impulse experienced during the collision is 200 Ns, use the information in the plot to calculate the peak force experienced during the collision. (b) Calculate the average force experienced during the collision.
47. Ophthalmologists use the properties of inelastic collisions to detect a disease of the eye called glaucoma. While a healthy eye at normal pressure is slightly spongy, glaucoma causes the eye to become rigid due to a buildup of pressure in the eye. An ocular tonometer helps test for glaucoma by sending a puff of air to collide with the eye and measuring its rebound velocity. How would the impulse delivered to the puff of air against a healthy eye compare to an eye with glaucoma?A. The impulse delivered to the air puff by the healthy eye would be greater due to the higher rebound velocity of the air puff. B. The impulse delivered to the air puff by the glaucoma eye would be greater due to the higher rebound velocity of the air puff. C. The impulse delivered to the air puff by the healthy eye would be greater due to the lower rebound velocity of the air puff. D. The impulse delivered to the air puff by the glaucoma eye would be greater due to the lower rebound velocity of the air…
Which of the following gives the closest value of the speed of the ball just after impact? 12.25 21.2 10.61 15
Julia pass a basketball to her friend Luna by making a bounce pass. Julia throws a 0.60 kg basketball toward the floor at a speed of 7 m/s and at an angle of 65 degrees with respect to the vertical. If the ball rebounds with the same speed and angle towards Luna, calculate the impulse delivered to the ball by the floor. Choose up and away from Julia as your positive direction.
A football player is preparing to punt the ball down the field. He drops the ball from rest and it falls vertically 1.0 m down ongo his foot. After he kicks it, the ball leaves the foot with a speed of 18 m/s at an angle of 51 degrees above the horizontal. 1) what is the magnitude of the impulse delivered to the ball in Kg meters per sec as he kicks it? An american football has a mass of 420 g 2) at what angle in degrees above the horizontal is the impulse delivered to the football?
#B2
9. An athlete who is initially at rest in a squatted position jumps vertically upward and then lands going back to the original squatted position (ending at rest with the same center of mass height as at the start). The time period under consideration begins just before the athlete starts the upward motion and ends just after she has landed and comes to rest back in the squatted position. Compare the magnitude and directions of the impulse from the force of the ground on the athlete to the impulse from gravity on the athlete during this time period. Note: there are no other significant forces other than the ground and gravity acting on the athlete during this time period. of
A 71.1-kg basketball player jumps vertically and leaves the floor with a velocity of 1.87 m/s upward. (a) What impulse does the player experience? magnitude N.S direction ---Select- (b) What force does the floor exert on the player before the jump? magnitude direction ---Select- (c) What is the total average force exerted by the floor on the player if the player is in contact with the floor for 0.450 s during the jump? magnitude direction ---Select--