6. A truck runs into a pile of sand, moving 0.80 m as it slows to a stop. The magnitude of the work that the sand does on the
truck is 6.0 X 10^5J. (a) Determine the average force that the
sand exerts on the truck. (b) Did the sand do positive or nega-
tive work? (c) How does the average force change if the stop-
ping distance is doubled? Indicate any assumptions you made.

potential energy is directly proportional to height.

more height = more potential energy.

greatest increase in height = greatest increase in potential energy

where are the points with the greatest increase in height ?

has to be c-e or d-e .

weight of the box is given as

here this is placed on the inclined of angle 42 degree

now this weight will have two components one is along the incline other is perpendicular to it

so here we need to apply a force parallel to incline opposite to its component of weight

so here the component of weight is given as

here we have

so it requires 75 n force to move it upwards

the right answer is 0.3 meters per second

inverse v=i*r

nice nice