a particle is pulled along a curved surface very slowly the coefficient of kinetic friction between the particle and the surface area is 0.4 the heat generated during the pulling of particle from lowest point a to the topmost point b is equal to(the mass of a particle equal to 5g)
Answers
Answer:
S.A=0.4
m=5g
h=10m
Explanation:
thn the particles move upwards by the source of heat generation of the particles
given info : a particle is pulled along a curved surface very slowly the coefficient of kinetic friction between the particle and the surface area is 0.4.
To find : the heat generated during the pulling of particle from lowest point a to the topmost point b is equal to(the mass of a particle equal to 5g)...
solution : let an instant, particle makes an angle θ with horizontal.
friction force, fk = μN
now work done by the friction, Wf = ∫fk.ds cos180° [ here angle between frictional force and displacement is 180° because both are in opposite directions ]
= -∫μN ds
N = normal reaction of particle at that instant = mgcosθ
now, Wf = -∫μmgcosθ ds
= -μmg∫dscosθ
here dscosθ = dx
so, Wf = -μmg∫dx = -μmgx
from work energy theorem,
work done by force + Workdone by gravity + workdone by friction = kinetic energy
as particle is slowly pulled along the surface so, kinetic energy, ∆K = 0
work done by gravity = -mgy
so, work done by force - μmgx - mgy = 0
⇒work done by force = mg(μx + y)
here m = 0.005kg , g = 10 m/s² , μ = 0.4, x = 5 m and y = 10m
so, work dome, W = 0.005 × 10(0.4 × 5 + 10)
= 0.05 × (12)
= 0.6 J
therefore heat generated during the pulling of particle is 0.6 J