A backpack has a mass of 8 kg. It is lifted and given 54.9 J of gravitational potential energy. How high is it lifted? Acceleration due to gravity is g = 9.8
m/s

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 ?

How is acceleration calculated? a. initial velocity - final velocity / timeb. initial velocity + final velocity / timec. final velocity - initial velocity / timed. final velocity / timele select the best answer from the choices provided0oood00save and exitnextmark this and return

Determine the maximum r-value of the polar equation r =3+3 cos 0