King Fahd University of Petroleum & Minerals Mechanical Engineering Dynamics ME 201 BY Dr. Meyassar N. Al-Haddad Lecture # 14

Projectile Determine the speed at which the basketball at A must be thrown at the angle of 30o so that it makes it to the basket at B. At what speed does it pass through the hoop?

A ball traveling at 25 m/s drive off of the edge of a cliff 50 m high A ball traveling at 25 m/s drive off of the edge of a cliff 50 m high. Where do they land? Horizontally x = x0 + (v0)x t 25 m/s x = 25 *3.19 = 79.8 m 79.8 m Initial Conditions vx = 25 m/s vy0 = 0 m/s a =- 9.8 m/s2 t = 0 y0 = 0 m y =- 50 m x0 =0 m Vertically v = v0-gt y = y0 + v0t + 1/2gt2 …. v2 = v02 - 2g(y-y0)…. -50 = 0+0+1/2(-9.8)t2 … t = 3.19 s V2 = -2(9.8)(-50-0)… V = 31.3 m/s

Example 13-4 m A= 3 kg m B= 5 kg From rest vB= ? In 2 second Block A Block B

Problem VA = ? 2Sc + SA = L 2ac + aA = 0 aA = -2ac

Relative motion At the instant shown, cars A and B are traveling at the speeds shown. If B is accelerating at 1200 km/h2 while A maintains a constant speed, determine the velocity and acceleration of A with respect to B.

Problem 13.8 v = 65 ft/s aA = ? smooth slope W = 150 lb

Polar and Cylindrical The slotted fork is rotating about O at a constant rate of 3 rad/s. Determine the radial and transverse components of velocity and acceleration of the pin A at the instant q = 360o. The path is defined by the spiral groove r = (5+q/p) in., where q is in radians.

Example 12-20

Problem 13-89 Smooth Horizontal m = 0.5 kg r = (0.5 q) q = 0.5 t2 rad Applied force Normal force t = 2 s. r y y y q

q r Problem m=2 kg Smooth horizontal r = 0.4 q Ptangent = ? N N=? P At q = 45o P N r q

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