A3.0-kilogram toy dump truck moving with a speed of 4.0 m/s starts up a ramp. how high does the truck roll before it stops?

Before it reaches the ramp, the toy's kinetic energy is

                                        (1/2) (mass) (speed²)

                                   =   (1/2) (3 kg) (16 m²/s²)

                                   =          24 Joules .

On the way up the ramp, its kinetic energy will change to
gravitational potential energy, and it'll stop when it's height
gives it  24 joules of potential energy.

         Potential energy  =  (mass) (gravity) (height)

                    24  joules  =  (3 kg) (9.8 m/s²) (height)

Divide each side by  29.4 kg-m/s²  (that's the same as 29.4 newtons):

                    Height  =  24 joules / 29.4 newtons

                                =      0.816 meter higher than the bottom of the ramp.