A worker with spikes on his shoes pulls on rope that is attached to a box that is resting on a flat, frictionless frozen lake. T
he box has mass m, and the worker pulls with a constant tension T at an angle θ = 40 ∘ above the horizontal. There is a strong headwind on the lake, which produces a horizontal force Fw that is pointed in the opposite direction than the box is being pulled. Draw a free-body diagram for this system. Assume that the worker pulls the box to the right. If the wind force has a magnitude of 30 N, with what tension must the worker pull in order to move the box at a constant velocity?
1 answer:
Answer:
a
The free body diagram is shown on the first uploaded image
b
The tension on the rope is
Explanation:
From the question we are told that
The mass of the box is m
The tension on the box is T
The angle at which it is pulled is
The force produced by the strong head wind is
At equilibrium the net force acting on the block along the horizontal axis is zero i.e
substituting values
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Answer:
If both the radius and frequency are doubled, then the tension is increased 8 times.
Explanation:
The radial acceleration (), measured in meters per square second, experimented by the moving end of the string is determined by the following kinematic formula:
(1)
Where:
- Frequency, measured in hertz.
- Radius of rotation, measured in meters.
From Second Newton's Law, the centripetal acceleration is due to the existence of tension (), measured in newtons, through the string, then we derive the following model:
(2)
Where is the mass of the object, measured in kilograms.
By applying (1) in (2), we have the following formula:
(3)
From where we conclude that tension is directly proportional to the radius and the square of frequency. Then, if radius and frequency are doubled, then the ratio between tensions is:
(4)
If both the radius and frequency are doubled, then the tension is increased 8 times.