Question40 (Fig. P8.40). (a) Show that if thesphere is released from a heightbelow that of the peg, it will returdto this height after the string strikesthe peg. (b) Show that if the pendu-Peglum is released from rest at the hor-izontal position (0swing in a complete circle centered90°) and is toon thepeg,the minimum value of dFigure P8.40must be 3L/5.41. A ball whirls around in a vertical circle at the end of aSstring. The other end of the string is fixed at the cen- m. (b) Find the speed of the block as itequilibrium point. (c) What is the speedt is at a position x,/2 = 3.00 cm? (d) Whypart (c) half the answer to part (b)?platform, starting from rest with the ropes at an angle 0, =60.0° with respect to the vertical. As she swings several timesback and forth in a circular arc, she forgets her frustrationrelated to the hand-strength test. Assume the size of theperformer's body is small compared to the length l and airresistance is negligible.i39. An airplane of mass 1.50 × 10ª kg is in level flight, initiallyQC moving at 60.0 m/s. The resistive force exerted by air onthe airplane has a magnitude of 4.0 × 10ª N. By Newton'sthird law, if the engines exert a force on the exhaust gasesto expel them out of the back of the engine, the exhaustgases exert a force on the engines in the direction of theairplane's travel. This force is called thrust, and the valueof the thrust in this situation is 7.50 × 104 N. (a) Is the workdone by the exhaust gases on the airplane during sometime interval equal to the change in the airplane's kineticenergy? Explain. (b) Find the speed of the airplane after ithas traveled 5.0 × 10² m.mx = 0x = x;/2x= X;Figure P8.35years ago, the Greek teacher Aristotlez called Physics. Put into more precise ter-age is from the end of its Section Eta:40. A pendulum, comprising a light string of length L and awer of an agent causing motion; w, thethe distance covered; and At, the timed. Then (1) a power equal to P will inSS small sphere, swings in the vertical plane. The string hitsa peg located a distance d below the point of suspensionge Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s).d th: 238 of 1370 ent does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it.

Answered: Image /qna-images/answer/fae280fe-340c-4367-943f-fc8c816eddda.jpg

(Fig. P8.40). (a) Show that if the sphere is released from a height below that of the it will return peg, L d to this height after the string strikes peg. (b) Show that if the pendu- the Pege lum is released from rest at the hor- izontal position (0 = 90°) and is to swing in a complete circle centered on the peg, the minimum value of d must be 3L/5. Figure P8.40