Ount 10. The friction of the air causes a verticalretardation equal to 10% of the accelerationdue to gravity. Take g=10m/s. Themaximum height and time to reach themaximum height will be decreased by1) 9%, 9%2) 11%, 11%359%, 10%4) 11%,9%

Ount 10. The friction of the air causes a verticalretardation equal

1.	Ount 10. The friction of the air causes a verticalretardation equal to 10% of the accelerationdue to gravity. Take g=10m/s. Themaximum height and time to reach themaximum height will be decreased by1) 9%, 9%2) 11%, 11%359%, 10%4) 11%,9%
Answer» correct OPTION is B.Given,RETARDATION =10%If there is no friction then,By the equation of the motion,v2=u2+2ghv=0h=2gu2Now,When there is air resistance 10% of the gravity.geff=g+0.1g=1.1gThe maximum HEIGHT will be,h1=2gefu2Therefore, the difference is h1−hu22gef−2gu2So,Change in height is:2gu2−2gefu2=2gu2−2gu2(1−1011)THUS the PERCENTAGE change in height is:=2gu2