13) C option if false .
considering a ball kept at a height 'h' and earth as a system .
as the ball is lowered the K.E increases even though no external force is applied on the system .
1) 4 point masses A,B,C,D are placed at coplanar but non collinear points,If P is centre of mass of A,B,C,D ..identify correct statements
a)P must lie within quad ABCD
b)P must lie on a line joining any of two points A,B,C,D
c)P may or may not coinicide with point masses
d)P lies inside or on edge of atleast one of the triangles formed by taking any of the four pts.
2)Let v and a be inst velocities and accelration of a particle moving in the plane.Then rate of change of velocity dv/dt is given by
a)lal
b)v.a/v
c)componnet of a parallel to v
d)componnet of a perpendicular v
(dbt in a,b, option)
3)Identify correct statements
a)work done by static firiction is always zero
b)work done by kinetic friciton can be positive also
c)KE of system cant be increased without applying any external force on system
d)WE theorm is valid in non inertial frame also
(dbt in c option)
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5 Answers
112) the second option is tangential acc or the compnent of acc in the direction of vel u and i cant understand option a
106Q2. If it is rate of change of speed then option (b)
If it is rate of change of velocity, then option (a)
