A nearby star has a parallax of 0.2 arc seconds. What is its distance?
1 answer:
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Answer:
The coefficient of kinetic friction is 0.382.
Explanation:
Given:
Angle of inclination is, °
Mass of package is,
Initial speed of package is,
Final speed of the package at the bottom is,
Distance of travel along the incline is,
Acceleration due to gravity is,
Let the coefficient of kinetic friction be .
Now, the frictional force will be acting along the incline but in the direction opposite to the direction of motion.
So, the net acceleration acting on the package will be up the incline and is equal to:
----------------- 1
Now, using equation of motion, we have:
Solving for 'a', we get:
Now, plug in the value of 'a' in equation (1). This gives,
( Neglecting negative sign)
Plug in all the given values and solve for . This gives,
Therefore, the coefficient of kinetic friction is 0.382.
Answer:
work output is always less than work input - the ratio is less than 1.
Explanation:
This principle comes from the fact that a machine or system cannot produce more work than is supplied to it, because this would violate the energy conservation law (work is a type of mechanical energy).
In theoretical machines called "ideal machines" the input work is the same as the output work, but these machines are only theoretical because in real applications there is always some type of energy loss, either in heat produced by a machine or processes for its operation, for this reason the output work is always less than the input work.
Regarding the ratio work output to work input:
because work input WI is always greater than work output WO.