A roller coaster begins at rest 120 m above the ground, as shown. Assume no friction from the wheels and air, and that
no energy is lost to heat, sound, and so on. The radius of the
loop is 40 m. Find the speed of the roller coaster at points E
and E.
Note:- Use g = 10 m/s^2

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

according to jean piaget, in what stage of cognitive development are children able to understand conservation task?

b. preoperational

just took it