Ask a Doubt
Request a call back

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

CBSE Class 9 Answered

a body of mass 5 kg is thrown vertically upward with a velocity of 20 metre per second find 1- initial kinetic energy 2-kinetic energy and potential energy after 1 second( given g  =10 /s^2)
Asked by karanbora625 | 26 Oct, 2019, 06:44: PM
answered-by-expert Expert Answer
m = 5 kg
u = 20 m/s (Initial velocity)
Initial kinetic energy, 
K.E. = 1/2 mv2 
K.E = 1/2 × (5) (20)2 
K.E. = 1000 J 
 
Thus, initial kinetic energy is 1000 J 
 
Now, the speed with which the body is thrown is 20 m/s 
Thus, height reached by body after 1 s is, 
 
h = ut + 0.5 gt2 
h = (20) (1) +0.5 (-10) (1) ... (negative sign for g indicates that the body is thrown against the gravity)
h = 15 m 
 
P.E. = mgh = 5 × 10 × 15 = 750 J
The initial kinetic energy = total energy required to throw the body
Thus, 
Kinetic energy after 1 s is, 
T.E = P.E. + K.E. (after 1 s)
1000 J = 750 J + K.E. (after 1 s) 
K.E (after 1 s) = 1000 - 750 = 250 J 
 
 
 
Thus, after 1 s, the kinetic energy will get completely converted 
Answered by Shiwani Sawant | 28 Oct, 2019, 06:36: PM

Application Videos

Concept Videos

Multiple Choice Questions Practice Test
Answered Unanswered My Questions My Answers
CBSE 9 - Physics
An object of mass 1kg is falling from the height h=10m.calculate a) the total energy of an object at h=10m b) potential energy of the object when it is at h=4m c) kinetic energy of the object when it is at h=4m d) what will be the speed of the object when it hits the ground
Asked by mailtoparvathyprajith | 08 Feb, 2024, 06:45: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Physics
when an arrow is shot from its bow it has kinetic Energy. From where does it get the kinetic Energy
Asked by mailtoparvathyprajith | 06 Feb, 2024, 08:44: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Physics
Calculate the work required to be done to stop a car of 1500 kg moving at a velocity of 60 km hour
Asked by vkjainj56 | 30 Nov, 2023, 12:00: AM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Physics
kinematics
question image
Asked by palagarapapamma1982 | 26 Sep, 2023, 08:50: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Physics
what is energy
Asked by divyanshu.3082007 | 03 Feb, 2022, 05:21: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Physics
did the kilometer is a SI unit of measurement
Asked by contactus.topperlearning | 03 Oct, 2020, 07:18: AM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Physics
Which energy source is renewable  
Asked by Pm2895089 | 17 May, 2020, 10:09: AM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Physics
Please solve. 
question image
Asked by kiranbora10 | 02 Apr, 2020, 12:42: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Physics
When do we say that work is done ?
Asked by kavitavinaysharma | 23 Jan, 2020, 10:01: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Physics
What is potential energy,kinetical energy,power?
Asked by mohammedfayas007 | 17 Jan, 2020, 09:17: 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
×