Question
mentsd graph FInd the helght from which you would have to drop a ball so that it would have a speed of 9.7 m/s just before It hits the ground Need Help? Taik to Taor nment5d Linear inal one di Answors SerCP8 5.P.024 otes je healt A 210-N child is in a swing that Is attached to ropes 1.90 m long. Flnd the gravitational potential energy assoclated with the child relative to her lowest position at the following times. (a) when the ropes are horlzontal 399 (b) when the ropes make a 29.0° angle with the vertical 57.925 Your response differs from the correct answer by more than 10%. Double check your calculations. (c) when the child is at the bottom of the circular arg Need Help? ERead in. LteiktoaTutor1 7
Explanation / Answer
Q(6)
Using equation of motion
v2-u2 = 2as
where a = g = 9.8 m/s/s and u = 0 m/s
v2 = 2*g*h
9.72 = 2*9.8*h
h = 4.8 m
Q(7)
(a)
when the ropes are horizontal
E = m*g*h
E = 210*1.90
E = 399 J
(b)
when the ropes make a 29.0 o angle with the vertical
h2 = (1-cos29 o)h
E2 = 210*(1 - cos 29 o)*1.90
E2 = 50 J
(c)
when the child is at the bottom of the circular arc
0 J