Figure shows a massless spring fixed at the bottom end of an inclined of inclination ${37}^0$ (tan ${37}^0$ = 3/4). A small block of mass 2kg start slipping down the incline from a point 4.8 m away from free end of spring. The block compresses the spring by 20 cm, stops momentarily and then rebounds through a distance 1 m up the inclined, then ( $g=10m/s^2$ )