Jack put on his bag-pack of weight 120 N. He then starts running on level ground for 100 m before he started to climb up a ladder up a height of 10 m. How much work was done?
From Physics point of view, no work is done on pack at level ground. Reason: Lift is perpendicular to movement. Work is done on pack only when Jack climbs up the ladder. Work done, W = F x s = 120 x 10 = 1200 J or 1.2 kJ
An object in free fall means the object is falling freely, under the influence of gravity
When the object is at the highest position , the GPE is at maximum and KE is zero . When the object is falling , the GPE decreases as it loses height, and the KE increases At the lowest position , the KE is at maximum and GPE is zero .