1 )
A mass of 2.9 kg is suspended from a string of length 50 cm and it is at rest .
Another body of mass 0.1 kg moving horizontally with velocity 150 m / s ,
strikes and sticks to it . What is tension in the string , when it makes
angle 60 degree with vertical ?
Solution : -
. .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . .
2
) Formula for tension in the string is :
-
T – mg = ma .
. .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . .
3 )
The escape velocity from the earth’s surface is 11 km / s . A certain planet has radius twice
that of earth but its mean density is the same as that of earth . The value of
escape velocity from this planet would be : -
A ) 11 km / s , B
) 22 km / s ,
C ) 43 km / s , D
) None of these ,
Correct
Answer : - B ) 22 km / s ,
Solution : -
. .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . .
