Question

Please help!!

B) Captain Kiddo is standing on the edge of a cliff at some height above the ocean. She throws one ball straight up with initial speed v and then throws another ball straight down with the same initial speed. Which ball has the larger speed when it hits the ocean? C) Captain Kiddo is now thinking about vectors .. can two vectors having different magnitudes be combined to give a zero resultant? Can three vectors?

Answer 1

(B) The third equation of motion for the ball thrown below the cliff is represented as follows: v2 = u. +2gh Here, h is the height of the cliff, u, is the initial speed, g is the acceleration due to gravity, and v is the final velocity. The value of gis positive in downward direction and the value of g is negative for upward direction. For ball A, substitute v, for v and v for u, in equation v2 = u; +2gh and rearrange it for (v.) =v2 +2gh v. = /v2 +2gh The maximum height is H. The final velocity at the maximum height is 0 m/s. For maximum height in upward motion, substitute H, v for u., 0 m/s for v, and -g for g in equation v2 =u: +2gh. (0 m/s) = 12 +28(-H) The total height at the maximum height is represented as follows: Hotal = h+H =h+ 12 2g The initial velocity at the maximum height is 0 m/s. For ball B, substitute 0 m/s for u, v, for v, and h+ for Hotel (vs)*=(0 m/s)* +29|htm vz = 23h+v2 The velocity of the ball A and the ball B is same. Therefore, both the balls hit the ocean with the same speed. (C) The conditions for two vectors to give zero resultant are represented as follows: • The magnitude of the two vectors must be same • The direction of two vectors must be opposite. Therefore, from the above explanation the resultant of two vectors of different magnitudes is not zero. Consider three vectors of different magnitudes are represented as follows: ā=41 b=3 ē =- The resultant of three vectors is represented as follows: d=a+b+c = (41)+(31)+(-7) =0 Therefore, the resultant of three vectors of different magnitudes is zero.