1. Peter does 3,000 joules (1) of work by moving an object 40 meters (m). What is the force that Peter applies to the object?​

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 ?

Amira pulls a 3 pound wagon 4 feet. how much work has she done?

Acar travels in reverse. it covers 150 meters in 12 seconds what is the velocity of the car what is the speed of the car