MCQ A body of mass 5kg is pushed for distance x with accleration a. Then workdone against static friction is

1.ma*X cosB
2.ma*X sinB
3.zero
4.ma/X

Space-time metric ds2= -dt2+at2dx2+bt2dy2+ct2dz2 (a)how does the area of a rectangle with vertices at ( x=0, y=0, z=0 ), (1,0,0 ), ( 0,1,0 ) and (1,1,0 ) changes with time? (b) if a photon moving in the x direction starts from the origin at t=1, when does it reach x=l? (ds=0 for the trajectory of a photon.) (c) the proper time for a particle is defined by cd=ds. what is the proper time for a particle to move along the trajectory ( x(t)=t, y(t)=0, z(t)=0 ) from t=0 to 1 ? what is the condition on the parameter a so that the velocity of the particle never exceeds the speed of light ?

From 0 to 5 seconds john pushed a box 5 meters. from 5 to 10 seconds, paul pushed the same box another 5 meters. who did more work? a. john b. paul c. john and paul did the same amount of work.

Often called simply "velocity," this is the velocity of an object at a particular moment in time.