old exam problem!

في أحد الأولد اقزام وجدت هذا السؤال
كيف أطلع a عند الثانية 5 ؟
وشكرا

A 20 kg ball is travelling in a frictionless track along positive x-direction and its velocity/time graph is shown in Figure 2. The force experienced by the ball at 5th second is:
(Force is taken positive if it acts along positive x-axis)

A) 20 N
B) − 40 N
C) Zero
D) 5 N
E) − 10N
الجواب A طبعا بس ابي افهم كيف

slope of the graph velocity vs time represents the acceleration

take the portion of t 0, 10] The slope is 1

F = ma = 20 x 1 = 20

from 0 to 10 is same as from 0 to 5 ?

thank you

yes because the slope from 0 to 10 is the same which is 1
accelereation at any time between 0 seconds and 10 seconds is 1

يعطيك العافية :thumbsup: