The box stopped moving because there was a negative acceleration in the x direction caused by friction.
To find the average speed, simply divide the displacement by time: 10 / 2 = 5 m/s
Explanation:
Terminal velocity is given by:
Here, m is the mass of the falling object, g is the gravitational acceleration, is the drag coefficient, is the fluid density through which the object is falling, and A is the projected area of the object. in this case the projected area is given by:
Recall that drag coefficient for a horizontal skydiver is equal to 1 and air density is .
Without drag contribution the motion of the person is an uniformly accelerated motion, thus:
Solids are the best at conducting heat.