Question

8. A tripod on the ground, holds an eyepiece turned upward such that when one looks through the eye piece they can see the top the building. If the angle between the eye piece and the horizontal is 38 degrees, the ladder is 7m long and the building is 6 m high, how high is the eyepiece above the ground? 9. A rock is thrown upward from the top of a 75 m tower with an initial velocity of 22 m/s. a.) How long does it take for the rock to hit the ground?

Answer 1

Q.7 solution: Given Height of Tower = 2 75m Initial veloc velocity u= 22 m/s final velocity o=0 m/s Now we know here acceleration will be =-10 m/s2 Height = distance travels sy it it in wpward direction 4²_u' 0-(22) ² a=-9 S = S = -2x 10 ga => S= 484 = 24.2 m 20 Time taken to reach this distance will be t=en 0-22 lo 2.2 S = t a of the tower of so to reach the its initial velouty is zero, so U=0, so it reaches 24.2 m 24.2m from the top top of height 75m. ground the rock has to cover Se 24.2 + 75 - 99.2 m when it starts falling from 99.2 m above the ground, its initial a=g= s=utt 99.25 ㅗ xlox+2 -> t = 4.45 sec Etz Now total time taken the rock to touch the is t-titt = 2.2+4.45= = 2.2 74.45 = 6.65 Seconds ſt = lomas Hence +19t2 2 by 6.655