Got Homework?
Connect with other students for help. It's a free community.
Here's the question you clicked on:
 0 viewing
mayankdevnani
Group Title
A body of mass 2 kg is thrown up vertically with a kinetic energy of 490 J.If the acceleration due to gravity is 9.8 m/s^2, the height at which the kinetic energy of the body becomes half of the original value is 
a) 50 m
b) 25 m
c) 12.5 m
d) 10 m
 one year ago
 one year ago
mayankdevnani Group Title
A body of mass 2 kg is thrown up vertically with a kinetic energy of 490 J.If the acceleration due to gravity is 9.8 m/s^2, the height at which the kinetic energy of the body becomes half of the original value is  a) 50 m b) 25 m c) 12.5 m d) 10 m
 one year ago
 one year ago

This Question is Closed

mayankdevnani Group TitleBest ResponseYou've already chosen the best response.1
@Hero @hartnn @Chlorophyll @robtobey @sauravshakya @kropot72 @jiteshmeghwal9 @hba
 one year ago

mayankdevnani Group TitleBest ResponseYou've already chosen the best response.1
@mathslover have a look:)
 one year ago

mathslover Group TitleBest ResponseYou've already chosen the best response.2
First find the original value ... what you get?
 one year ago

mayankdevnani Group TitleBest ResponseYou've already chosen the best response.1
original value????
 one year ago

mathslover Group TitleBest ResponseYou've already chosen the best response.2
sorry i think it is given
 one year ago

sauravshakya Group TitleBest ResponseYou've already chosen the best response.0
Potential energy of the body =mgh
 one year ago

sauravshakya Group TitleBest ResponseYou've already chosen the best response.0
u know it?
 one year ago

mayankdevnani Group TitleBest ResponseYou've already chosen the best response.1
ok!!
 one year ago

mathslover Group TitleBest ResponseYou've already chosen the best response.2
490 J = KE (ORIGINAL)
 one year ago

mathslover Group TitleBest ResponseYou've already chosen the best response.2
half of it will be 490 /2 J = 245 J , correct?
 one year ago

mayankdevnani Group TitleBest ResponseYou've already chosen the best response.1
why you do the half the K.E @mathslover
 one year ago

mathslover Group TitleBest ResponseYou've already chosen the best response.2
@mayankdevnani because we have to find the height when the new kinetic energy equals half of the original one. ...
 one year ago

mayankdevnani Group TitleBest ResponseYou've already chosen the best response.1
@03225186213
 one year ago

mathslover Group TitleBest ResponseYou've already chosen the best response.2
therefore the new kinetic energy must be equal to 245 Joules.
 one year ago

mayankdevnani Group TitleBest ResponseYou've already chosen the best response.1
correct!!!
 one year ago

mathslover Group TitleBest ResponseYou've already chosen the best response.2
therefore we have : 1/2 m v^2 = 245 J 1/2 m (u^2 + 2gh ) = 245 J 1/2 m (2gh) = 245 mgh = 245 J 2 kg * 9.8 * h = 245
 one year ago

mathslover Group TitleBest ResponseYou've already chosen the best response.2
solve for h and you will get h = 12.5 m
 one year ago

mayankdevnani Group TitleBest ResponseYou've already chosen the best response.1
1/2 m (u^2 + 2gh ) = 245 J ??????????????
 one year ago

mathslover Group TitleBest ResponseYou've already chosen the best response.2
got it?
 one year ago

mayankdevnani Group TitleBest ResponseYou've already chosen the best response.1
no!!!!
 one year ago

mayankdevnani Group TitleBest ResponseYou've already chosen the best response.1
1/2 m (u^2 + 2gh ) = 245 J this line!!!
 one year ago

mathslover Group TitleBest ResponseYou've already chosen the best response.2
since v^2 = u^2 + 2gh therefore..
 one year ago

mayankdevnani Group TitleBest ResponseYou've already chosen the best response.1
thnx.... i got it @mathslover
 one year ago

mathslover Group TitleBest ResponseYou've already chosen the best response.2
good,...
 one year ago

mayankdevnani Group TitleBest ResponseYou've already chosen the best response.1
let @03225186213 be answer.... plz wait
 one year ago

03225186213 Group TitleBest ResponseYou've already chosen the best response.0
1/2 mv^2=mgh 490/2=2 (9.8)h h= 9.8 because it is moving against gravity
 one year ago

mathslover Group TitleBest ResponseYou've already chosen the best response.2
@03225186213 same I thought BUT it is given in the quest. that g = 9.8 m/s^2
 one year ago

mayankdevnani Group TitleBest ResponseYou've already chosen the best response.1
yaaa you are correct thnx @mathslover and @03225186213
 one year ago

03225186213 Group TitleBest ResponseYou've already chosen the best response.0
welcome
 one year ago
See more questions >>>
Your question is ready. Sign up for free to start getting answers.
spraguer
(Moderator)
5
→ View Detailed Profile
is replying to Can someone tell me what button the professor is hitting...
23
 Teamwork 19 Teammate
 Problem Solving 19 Hero
 Engagement 19 Mad Hatter
 You have blocked this person.
 ✔ You're a fan Checking fan status...
Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.