A BODY COVERS 4m IN 3rd SECOND AND 12m IN 5th SECOND. CALCULATE THE ACCELERATION, IF IT IS ACCELERATED UNIFORMLY. 

Asked by swarajtopper | 30th Jul, 2015, 09:41: PM

Expert Answer:

Given:
Distance moved in 3rd second, s3 = 4 m
Distance moved in 5th second, s5 = 12 m
By the equation of motion (uniform acceleration):
begin mathsize 14px style straight S subscript straight n equals straight u space plus space straight a open parentheses straight n minus 1 half close parentheses end style
where Sn is the distance travelled by a body in the nth second of its journey.
begin mathsize 14px style straight S subscript straight n equals straight u space plus space 1 half straight a space open parentheses 2 straight n minus 1 close parentheses 4 space equals space straight u space plus space 1 half straight a space left parenthesis 2 cross times 3 minus 1 right parenthesis space space space space.... space left parenthesis 1 right parenthesis 12 space equals space straight u space plus space 1 half straight a space left parenthesis 2 cross times 5 minus 1 right parenthesis space space space space space.... space left parenthesis 2 right parenthesis Solving space the space equation space left parenthesis 1 right parenthesis space and space left parenthesis 2 right parenthesis comma space we space get comma 8 space equals space 2 straight a straight a equals 8 over 2 equals 4 space straight m divided by straight s squared end style
Therefore, the acceleration of the body is 4 m/s2.

Answered by Faiza Lambe | 30th Jul, 2015, 11:13: PM