| ⇦ | 
| ⇨ |
A ball is dropped from a high rise platform at t = 0 starting from rest. After 6 seconds another ball is thrown downwards from the same platform with a speed v.The two balls meet at t = 18s. What is the value of v?(take g = 10 m/s²)
Options
(a) 75 m/s
(b) 55 m/s
(c) 40 m/s
(d) 60 m/s
Correct Answer:
75 m/s
Explanation:
Clearly distance moved by 1st ball in 18 s = distance moved by 2nd ball in 12 s. Now, distance moved in 18 s by 1st ball 1/2 x 10 x 18²
= 90 x 18 = 1620 m. Distance moved in 12 s by 2nd ball = ut + 1/2 gt²
1620 = 12v + 5 x 144
v = 135 – 60 = 75 ms
Related Questions:
- A police jeep is chasing a culprit going on a motorbike.The motorbike crosses
- Water falls from a height of 60m at the rate of 15 kg/s to operate a turbine
- A rod lies along the X-axis with one end at the origin and the other at x→∞. It carries
- In circular coil, when number of turns is doubled and resistance becomes 1/4th
- The kinetic energy needed to project a body of mass m from the surface of earth
Topics: Motion in Straight Line
(93)
Subject: Physics
(2479)
Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score
18000+ students are using NEETLab to improve their score. What about you?
Solve Previous Year MCQs, Mock Tests, Topicwise Practice Tests, Identify Weak Topics, Formula Flash cards and much more is available in NEETLab Android App to improve your NEET score.
Share this page with your friends
Leave a Reply