Question

A block of mass 5 kg is initially at rest on a rough horizontal surface having coefficient

of static friction µs = 0.5 and coefficient of kinetic friction µk = 0.3. A gradually

increasing horizontal force is applied for dragging it. Assuming g = 10 m/s2

, acceler-

ation of the block and dragging force acting on the block could be respectively given

by,

A. 7 m/s2

, 50 N B. 2 m/s2

, 25 N C. 0 m/s2

, 20 N D. 3 m/s2

,40 N​

Answer 1

Answer:

*taking all given things*

Mass 5kg

us 0.5

uk 0.3

g 10ms2

SOLUTION.

lim.friction -us ×N =0.5×5×10=25N

so force should be greater than 25 Newton atleast to move object.

kin.friction uk×N=0.3×5×10=15

making equation and trying option à values,

FORCE APPLIED -k.friction =m×a

50 -15=5 ×a

a =35÷5 =7ms2

hence the answer is option à