A block with mass m1 = 8.6 kg is on an incline with
an angle ? = 32� with respect to the horizontal. For the first
question there is no friction between the incline and the
block.
1) When there is
no friction, what is the magnitude of the acceleration of the
block?
2) Now with
friction, the acceleration is measured to be only a = 3.95
m/s2. What is the coefficient of
kinetic friction between the incline and the block?
3)
To keep the mass from accelerating, a spring is attached with
spring constant k = 168 N/m. What is the coefficient of static
friction if the spring must extend at least x = 14 cm from its
unstretched length to keep the block from moving down the
plane?
4)
The spring is replaced with a massless rope that pulls
horizontally to prevent the block from moving. What is the tension
in the rope?
5)
Now a new block is attached to the first block. The new block is
made of a different material and has a coefficient of static
friction ? = 0.94. What minimum mass is needed to keep the system
from accelerating?