Respuesta :
Answer:
a) 557 J b) 557 J
Explanation:
The force acting on the body has vertical and horizontal component
the vertical component of the acting on the body = F sinθ
the horizontal component of the force acting on the block = F cosθ
since the block is moving with constant speed
then the frictional force = F cosθ in the opposite direction
μk = frictional force / force of normal
force of normal = mg + f sinθ
μk ( mg + Fsinθ) = F cosθ
μkmg = F cosθ - μk Fsinθ = F ( cos 32 - 0.2sin32) = 0.2 × 9.81 × 27
F (0.848 - 0.10598) = 52.974
F = 52.974 / (0.848 - 0.10598) = 71.392 N
A) work done = Fd cosθ = 71.392 × 9.2 × cos32 = 557 J
B) the increase in thermal energy of the block-floor system = 557J since the frictional force is equal to the force in the horizontal direction.
