A woman on a bridge 83.3 m high sees a raft floating at a constant speed on the

Question

A woman on a bridge 83.3 m high sees a raft floating at a constant speed on the river below. She drops a stone from rest in an attempt to hit the raft. The stone is released when the raft has 8.34 m more to travel before passing under the bridge. The stone hits the water 4.65 m in front of the raft. Find the speed of the raft.

Explanation / Answer

A woman on a bridge 98.0 m high sees a raft floating at a constant speed on the river below. She drops a stone from rest in an attempt to hit the raft. The stone is released when the raft has 6.70 m more to travel before passing under the bridge. The stone hits the water 5.10 m in front of the raft. Find the speed of the raft. y=(1/2)gt^2 solving for t we get the time for the stone to reach the water. t=sqrt of 2y/g=4.47 s the raft traveled for 6.7+5.1 m=11.8m. traveling 11.8 m in 4.47 sec, the velocity is 2.64m/s woman on a bridge 76.0 m high sees a raft floating at a constant speed on the river below. She drops a stone from rest in an attempt to hit the raft. The stone is released when the raft has 8.70 m more to travel before passing under the bridge. The stone hits the water 6.60 m in front of the raft. Find the speed of the raft. Take the question in two shifts ==========================Women dropping a stone initial velocity of stone, u = 0m/s height from where stone is dropped, h = 76m acceleration = 9.8m/s^2 BY newton;s laws of motion, v^2=u^2 + 2as => v^2 = 2 x 9.8 x 76 => v^2 = 1489.6 => v = 38.59m/s By newton's laws of motion, v = u +at => t = (v-u)/a => t = 38.59/9.8 => t = 3.93s the time taken by stone is equal to the time taken by the raft to move from being 8.7m away from bridge to 6.6m ================================motion of raft S = 8.7 - 6.6 => S = 2.1m time to travel this distance = 3.93 therefore speed of raft = s/t = 2.1/3.93 = 0.53m/s.....(ANSWER) Hope this is what you want,.!! ================================= Wasiq Khurshid =================================

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.