563 - Physics Questions Answers
how far from earth we can see earth as a whole elliptical?{we can clearly see the earth
for getting the complete vision we should draw tangents at the extreme of major and minor axis of the earth, this will give a point of intersection for which height from centre of earth will be R√2 so height from earth surface will be R√2 - R = R(√2-1)
here R is used for radius of earth
This is approximate calculation only
A 20 cm long test tube (cylindrical) is inverted & pushed vertically down into the water . when the closed end is at water surface, how high has the water risen inside the tube? [p atm =10^5 N/m²]
Let the height of water in the tube is x cm. then according to PV = constant, calculate the pressure by (20-x) cm. column
then P0 + pressure by 20 cm water = pressure by (20-x) cm. column + pressure by x cm water column
A body is moving towards north with initial velocity of 13m/s. Its is subjected to a retardation of 2 m/s2 towards south.The distance travelled in 7th sec is ??
displacement of any particular sec. = u+at-(a/2)
here direction of motion is opposite to the direction of acceleration so formula will be u-at+(a/2)
displacement in 7th sec = 0
now we know that direction of motion will become south after 6.5 sec. so distance for last half sec = ut+(1/2)at2 = 1/4
same will be the distance for the first half sec of 7th. so total distance for 7th sec = 1/4 + 1/4 = 1/2