Consider a block and trolley system as shown in figure. If the coefficient of kinetic friction between the trolley and the surface is 0.04 , the acceleration of the system in ms−2 is : (Consider that the string is massless and unstretchable and the pulley is also massless and frictionless) :
(A)3
(B)4
(C)2✓ Correct
(D)1.2
Answer: (C)
Solution
For the block (20 kg) on the trolley connected over a pulley to the hanging 6 kg block, with an applied 60 N force and kinetic friction under the trolley:
fk=μN=0.04×20g=0.04×20×10=8N
Applying Newton's second law to the whole system (net driving force minus friction, total mass 26 kg):
a=20+660−8=2652=2m/s2
JEE Main · 2024 · 01 Feb 2024 · Shift 1 · Single correct option