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Before tackling this one, I must clean it up a bit.
-- I'll assume that the floor is horizontal under the box.
-- "Angle" means the difference between two directions, but the question specifies
only one of them ... the direction of the rope. I'll assume that the 60° is the angle
between the rope and the horizontal travel of the box, and that the rope and the
tension in it are both directed above the horizontal, i.e., sloped toward the ceiling,
not toward the floor.
Now we have something we can work with.
-- The horizontal component of the tension in the rope is 80 cos(60) = 40 N.
-- The box is sliding along at constant speed, so the horizontal forces on it are balanced.
That means that the friction force is also 40 N but backwards.
-- The weight of the box is (m g) = (10 x 9.8) = 98 N.
-- The coefficient of friction is friction force/weight = 40/98 = 40.8 %
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Why this solution is bogus, at least in part:
The other component of the tension in the rope ... the vertical one ... is 80 sin(60) = about 69.3 N.
That force is applied to the box at the point where the rope connects, and pulls
straight up at that point. Its effect must be to reduce the box's apparent weight
at that end, and by some complicated amount everywhere along the length of the
box. So the force of friction is also distributed along the length of the box in some
non-uniform and complicated way, and the aggregate apparent coefficient of friction
is some ugly integral of the contributions due to an element of weight at every
element of length/area from one end of the box to the other.
Am I over-thinking this ? ? Perhaps it would be best if I take a nap.
What else can I help you with?
Acceleration is an increase of speed during a given interval of time?
No. It is the change in velocity (not speed) during a given interval of time. It can be an increase or a decrease although a decrease is also called a deceleration.The distinction between velocity and speed can best be illustrated by an object going round in a circle at a constant speed. It is changing direction all the time so that its velocity is constantly changing. It is constantly accelerating even though it is travelling at constant speed.
When are final and initial velocities taken ball kicked at 30 degrees at 10ms?
Initial velocity is 10 m/s in the direction it was kicked. Final velocity is 0, when friction and air resistance finally causes it to come to a halt.
What is the shape of a displacement-time graph for an object that is constantly speeding up?
If the Object is falling at a constant velocity the shape of the graph would be linear. If the object is falling at a changing velocity (Accelerating) the shape of the graph would be exponential- "J' Shape.
What is the formula for calculating conveyor belt length?
Equations relating to conyeyor belt length, friction, lag, and velocity may be found at the indicated link(s).
If a skydiver has a starting velocity of 2 meter per seconds and falls straight down with no friction what is her velocity 5 seconds later?
v = vo + gt = 2(m/s) + 9.8(m/s2) x 5s = 51(m/s)
What does friction have to do with skydiving?
It determines your terminal velocity, depending on your drag coefficient.
Why is it easier to determine the coefficient of kinetic friction if the object moves with a constant velocity?
When an object is moving at a constant velocity, it means that the forces acting on it are balanced. In this case, the force of kinetic friction is equal and opposite to the applied force, making it easier to calculate the coefficient of kinetic friction using the known values of force and normal force.
What are the two factors that affect the friction force between two surfaces?
The strength of the force of friction depends on the types of surfaces involved and on how hard the surfaces push together.
How do you calculate the friction in a pulley?
To calculate the friction in a pulley, you can use the formula: Friction = µ * N, where µ is the coefficient of friction and N is the normal force acting on the pulley. The coefficient of friction represents how "rough" the surfaces in contact are. By multiplying the coefficient of friction with the normal force, you can determine the amount of friction in the pulley system.
What is the coefficient of friction in a 6 inch round duct with a velocity of 200cfm?
The coefficient of friction for air flow in a round duct is typically around 0.02. This coefficient may vary depending on factors such as surface roughness and airflow conditions.
How much force do you need to keep a block at a constant velocity why?
To keep a block at a constant velocity, you need to apply a force equal in magnitude but opposite in direction to the force of friction acting on the block. This force is called the kinetic friction force and is dependent on the coefficient of friction between the block and the surface it's on.
What are the factors which affect the coefficient of static friction?
Dry surfacesFor low surface pressures the friction is directly proportional to the pressure between the surfaces. As the pressure rises the friction factor rises slightly. At very high pressure the friction factor then quickly increases to seizingFor low surface pressures the coefficient of friction is independent of surface area.At low velocities the friction is independent of the relative surface velocity. At higher velocities the coefficent of friction decreases.Well lubricated surfacesThe friction resistance is almost independent of the specific pressure between the surfaces.At low pressures the friction varies directly as the relative surface speedAt high pressures the friction is high at low velocities falling as the velocity increases to a minimum at about 0,6m/s. The friction then rises in proportion the velocity 2.The friction is not so dependent of the surface materialsThe friction is related to the temperature which affects the viscosity of the lubricant
What does the coefficient of kinetic friction depend on?
The coefficient of friction is a scalar value with no dimension. It is simply a ratio of the force of friction between two objects, to the force pressing those objects together (often the normal force). Slippery surfaces have lower coefficient of friction than rough surfaces.
What force is needed to slide a 250-kg crate across the floor at constant velocity if the coefficient of sliding friction between a crate and a horizontal floor is 0.25?
The force needed to slide the crate at constant velocity is equal in magnitude but opposite in direction to the force of friction. The force of friction can be calculated as the product of the coefficient of friction and the normal force acting on the crate (weight of the crate). Therefore, the force needed would be 250 kg * 9.8 m/s^2 * 0.25 = 612.5 N.
What is the average value of coefficient of velocity in a submerged orifice?
The average value of the coefficient of velocity for a submerged orifice is typically around 0.97 to 0.99. This value represents the efficiency of the orifice in converting the potential energy of the fluid into kinetic energy.
What force is needed to slide a mass of 54 kg at a constant velocity along a surface on which the coeffcient of friction is 0.43?
The force needed to slide the mass at a constant velocity is equal in magnitude and opposite in direction to the frictional force. The frictional force is calculated as the coefficient of friction multiplied by the normal force (frictional force = coefficient of friction * normal force). Hence, the force needed would be 0.43 times the weight of the mass (force = coefficient of friction * mass * gravity).
What is the coefficient of velocity?
By itself there is none. A coefficient is the multiplying factor in a polynomial equation.
