Question
Question: Five persons A, B, C, D and E are pulling a cart of mass 100 kg on a smooth surface and cart is movi...
Five persons A, B, C, D and E are pulling a cart of mass 100 kg on a smooth surface and cart is moving with acceleration 3 m/s2 in east direction. When person 'A' stops pulling, it moves with acceleration 1 m/s2 in the west direction. When person 'B' stops pulling, it moves with acceleration 14 m/s2 in the north direction. The magnitude of acceleration of the cart when only A and B pull the cart keeping their directions same as the old directions, is –
A
26 m/s2
B
371ms2
C
25 m/s2
D
30 m/s2
Answer
25 m/s2
Explanation
Solution
When all are pulling
Fnet= 100 × 3i ……(1)
When 'A' stops
Fnet –FA = 100 × 1(–i) ……(2)
When 'B' stops
Fnet – FB = 100 × 24j
from these three get
FA + FB and solve