Question

27 In Fig. 6-31, two blocks
are connected over a pulley.
The mass of block A is 10 kg,
and the coefficient of kinetic
friction between A and the incline
is 0.20. Angle theta of the
incline is 30°. Block A slides
down the incline at constant
speed. What is the mass of
block B?

Answer 1

mass of block A is 10 kg = m_A

= 0.20

= 30^o

g = 9.8 m/sec²

using equation

T + m g cos = m g sin

T = m g ( sin - cos )

= 10 x g ( sin30 - 0.2 x cos30 )

T = 10 x g ( 0.5 - 0.1732 )

T = 10 g x 0.3267

we have

T = m_B g

m_B g = 10 g x 0.3267

m_B = 10 x 0.3267

so the mass of block B is m_B = 3.267 kg.