A crate is pushed up each of the two ramps shown in the diagram below. Based on the concept that simple machines make work easier, and assuming that both ramps are frictionless, which statement is true? Question 4 options: Ramp B requires less force than ramp A. Ramp A requires less force than ramp B. Ramp B raises the crate higher than ramp A. Ramp A raises the crate higher than ramp B.

Because its reliable.   there is no pollution  the chances of a radiation leak is low

the best answer for these questions would be:

1.            c. is smaller

2.            d) concrete operational

3.            b) interaction with the environment – the children interact with their environment can them learn more.

4.            a) parents who reason openly with children can limit a child’s cognitive ability.

You need to be more specific.  i really don't know what a "motion map" is.you can draw a graph of an object's position, distance, displacement, speed,velocity, or acceleration versus time, or you can draw a graph of the object's x-position versus its y-position and not give any information about time at all.if the graph presents position or displacement against time,  then constant velocity is a straight line . . i.e. a line that has  constant slope.if the graph shows speed against time, then constant velocityis a horizontal piece of line.if the graph shows acceleration against time, then constant  velocity is a piece of line that lies on the x-axis . . it's value is zero.