Ask a Doubt
Request a call back

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

CBSE Class 9 Answered

A car with a speed of 25m/s weighting 900 kg stops at a distance of 40 m . calculate the force exerted and the work done by the brakes
Asked by pahiroy1221 | 13 Aug, 2015, 08:06: PM
answered-by-expert Expert Answer
begin mathsize 12px style Given colon straight u space equals space 25 space straight m divided by straight s straight v space equals space 0 straight m space equals space 900 space kg straight s space equals space 40 space straight m straight v squared space minus space straight u squared space equals space 2 as 0 space minus space left parenthesis 25 right parenthesis squared equals space 2 space cross times space straight a space cross times 40 straight a space equals space minus fraction numerator 25 squared over denominator 2 space cross times space 40 end fraction space equals space minus space 7.81 space straight m divided by straight s squared Force space equals space straight m space cross times straight a space equals space 900 space cross times space minus space 7.81 straight F space equals space minus 7029 space straight N Negative space sign space indicates space that space straight a space force space exerted space against space the space car space to space stop space it. Work space done comma space straight W space equals space straight F space cross times space straight s space equals space 7029 space cross times space 40 straight W space equals space 281160 space straight J end style
Answered by Priyanka Kumbhar | 14 Aug, 2015, 08:51: AM

Application Videos

Concept Videos

Multiple Choice Questions Practice Test
Answered Unanswered My Questions My Answers
CBSE 9 - Physics
A boy throws a steel ball straight up. Consider the motion of the ball only after it has left the boy's hand but before it touches the ground and assume that forces exerted by the air are negligible. For these conditions, the force(s) acting on the ball is (are): a. A downward force of gravity along with a steadily decreasing upward force b. A steadily decreasing upward force from the moment it leaves the boy's hand until it reaches its highest point on the way down there is a steadily increasing downward force of gravity as the object gets closer to the earth c. Constant downward force of gravity along with an upward force that steadily decreases until the ball reaches it highest point on the way down there is only a constant downward force of gravity d. Constant downward force of gravity only
Asked by harshsrivastava8896606 | 17 Apr, 2023, 01:47: AM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Physics
what is the weight of an object at the centre of the earth 
Asked by advscjaglan | 09 Aug, 2022, 08:22: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Physics
what is Newton's contribution on gravitation?
Asked by munendramishra478 | 12 Jul, 2022, 08:42: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Physics
two satellites of a planet have period 32 day and 256 days if the radius of orbit of former is R, find the orbital radius of the letter
Asked by rk7213908 | 31 Mar, 2022, 12:28: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Physics
weight of the body is zero in free fall why?
Asked by rk7213908 | 21 Feb, 2022, 04:48: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Physics
my doubt is the value of G is 60673multiply10-11power but why we use some no in some different numericals like use of 6.6, some times 6.7 why please ans this ques now 🙏
Asked by mannatjohn920 | 15 Feb, 2022, 09:57: AM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Physics
Find the force of gravitational attraction between the earth (m = 6 x 1024 kg) and 80 kg man if he is standing at sea level. The distance of man from earth's center is 6.38 x 106 m.
Asked by sudiptaroy0607 | 08 Jan, 2022, 04:59: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Physics
a stone is released from the top of the tower of height 19.6 m calculate its final velocity just before touching the ground
Asked by mj2692076 | 31 Dec, 2021, 04:11: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Physics
what is gravitation
Asked by kalpanatiwaritiwari7030 | 22 Dec, 2021, 07:35: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Physics
how does the force of gravitation between two objects change when the distance between them is reduced to half
Asked by sonalichavan03.bpps | 19 Dec, 2021, 08:19: 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
×