Ask a Doubt
Request a call back

Join NOW to get access to exclusive study material for best results

CBSE Class 11-science Answered

A ball is thrown upwards from the ground with an initial speed of u. The ball is at a height of 80 m at two times. The time interval being 6 sec. Find u. 
Asked by Anil | 12 Jun, 2017, 09:45: AM
answered-by-expert Expert Answer
 
begin mathsize 12px style Given space that space straight s space equals space 80 space straight m space straight a space equals space straight g space equals space minus 10 space straight m divided by straight s Using space the space equation space straight s space equals space ut space plus 1 half at squared space comma space we space have rightwards arrow space 80 space equals space ut space plus space space 1 half space cross times space open parentheses negative 10 close parentheses space straight t squared rightwards arrow space 80 space equals space ut space minus space 5 straight t squared or space rightwards arrow space 5 straight t squared space minus space ut space plus space 80 space equals space 0 Solving space the space quadratic space equation comma space we space get straight t space equals space fraction numerator straight u space plus space square root of straight u squared minus 1600 end root over denominator 10 end fraction space and space space fraction numerator straight u space minus space square root of straight u squared minus 1600 end root over denominator 10 end fraction Now space it space is space given space that space fraction numerator straight u space plus space square root of straight u squared minus 1600 end root over denominator 10 end fraction space minus space space fraction numerator straight u space minus space square root of straight u squared minus 1600 end root over denominator 10 end fraction space equals space 6 or space fraction numerator space square root of straight u squared minus 1600 end root over denominator 5 end fraction space equals space 6 rightwards arrow space square root of straight u squared minus 1600 end root space equals space 30 rightwards arrow space straight u squared minus 1600 space equals space 900 rightwards arrow space straight u squared space equals space 2500 rightwards arrow space straight u space equals space plus-or-minus space 50 straight m divided by straight s Here space we space ignore space the space negative space signand space get straight u space equals space 50 space straight m divided by straight s end style
Answered by Yashvanti Jain | 12 Jun, 2017, 10:24: AM

Concept Videos

Multiple Choice Questions Practice Test
Answered Unanswered My Questions My Answers
CBSE 11-science - Physics
Q17. The velocity time relation of an electron starting from rest is given by v = kt where k = 6m / (s ^ 2) Calculate the distance traversed in 2 sec. 122
Asked by om636694 | 04 Mar, 2024, 09:10: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 11-science - Physics
state and prove law of conservation of energy in case of a freely falling bady
Asked by dhanapolla | 28 Jan, 2024, 10:40: AM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 11-science - Physics
if the linear momentum of a body is increased by 10% what will be the percentage change in it's kinetic energy
Asked by santoshyadav6673633 | 26 Jan, 2024, 04:55: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 11-science - Physics
obtain equations of motion for constant acceleration using calculus method
Asked by klvnsnthl | 25 Dec, 2023, 07:50: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 11-science - Physics
what is elevators
Asked by neerajchaurasiya651 | 10 Dec, 2023, 09:32: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 11-science - Physics
a mass of 0.1 kg falls freely under the action of gravity find the force acting on it it's momentum and kinetic energy after 10 sec ?
Asked by debasishbarik2006 | 17 Nov, 2023, 07:03: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 11-science - Physics
A stone is thrown upwards vertically. It has speed 10m/s when it reaches one half of its maximum height. Then find out how high it will rise?
Asked by udayanmazumder079 | 13 Jul, 2023, 09:21: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 11-science - Physics
An object starts from rest moves in constant acceleration A upto its max velocity and then retards at B until it comes to rest Cal the max velocity and the displacement if the total time of journey is T
Asked by sahamamoni597 | 27 Jun, 2023, 01:00: AM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 11-science - Physics
how to solve this
question image
Asked by sumityadv5665 | 24 Dec, 2022, 02:36: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 11-science - Physics
16dx2/dt2+ 25x = 0
question image
Asked by adityajaiswal80551 | 18 Dec, 2022, 06:29: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
My Class Videos Tests ₹ Plans Ask a Doubt
Get Latest Study Material for Academic year 24-25 Click here
×