[سر النبوغ]

اوووووووو ... معليش خوفتكم . ..
بس الموضوع ابسط من كدا ^^ وهذا السؤال من شبتر 7 ومن ملخصات د\ علي الزهراني
وهذا حل السؤال بس مو بالتفصيل :
(i) The work done by the force is
WF = F d cosθ= 50 × 10 × cos0= 500 J
Note that both the force and displacement are in the same direction.
(ii) The work done by the gravity force is
Wg = Fg d cosθ= Fg d cosθ= 2 × 9.8 × 5 × cos180 = - 98 J
(iii) The total work done is
WT= WF + Wg =500-98 =402 J
Therefore the change in the kinetic energy is
W =ΔK =K2 – K1= ½ m v2
2
Where the initial speed is zero. Hence the final speed is
v2
2 = 2ΔK/m = 2×402/10 = 80.4 (m/s)2
v2 = 9 m/s

وانتو افهموا الرموز المقربعة والى فهم افهمني