With over 600 muscles in the body we are able to do an array of motions. What is the difference between what big muscles, like the four in the quadriceps, can do and what those like the thirty in our hands can do

find the sum of the two horizontal vectors and the sum of the two vertical vectors

isoceles right angled triangle

the moving of the box is a result of centripetal force. think of that  as a car or a truck in this case creates a turn, the force of friction performing upon the turned wheels of the car runs centripetal force obligatory for circular motion for the things inside it.