Question
#7
the ground? e uanHow high does the rock get? (d) How fast does it hit the ground? (e) At what angle does it hit 6. A hang glider is flying in a horizontal cirele of radius 20 m, completing the cirele in a time period of 10 s. (a) What is the speed of the glider? (b) What is the tangential acceleration of the glider? (e) What is the radial acceleration of the glider? (d) Express this last answer in g's of acceleration. (e) How many gs of force would the pilot be experiencing? Would this be noticeable? 7. A boy uses a sling to throw a rock across the field by whirling the rock in a vertical cirele of radius 0.5 m frequency 2 Hz. If the rock is released when the sling makes an angle of 300 below the horizontal when the rock is at a height of 1 m above the ground, (a) how high will the rock rise above the ground and (ob) how far will it travel horizontally before hitting the ground? and
Explanation / Answer
7] a)Throwing speed v = wr = 2 pi f r = 2 pi *2*0.5 = 6.283 m/s
Angle of launch = 90-30 = 60 degree
maximum height = 1 + u^2 (sin theta)^2 /2g
= 1 + 6.283^2 *( sin 60 degree )^2 /19.8
= 2.495 m. answer
b]. time of flight T = 6.283 sin 60 degree /9.8 + sqrt(2*2.495/9.8)
= 1.269 s
Range = V cos theta *T
= 6.283 cos 60 degree * 1.269
= 3.99 m answer
