CH 5: Turning Effects of Forces

• When a force is exerted on a stationary body, it can cause the body to accelerate, move, and turn or spin about a fixed position, which is stated in Newton's second law: F = ma.
• The SI unit of moment is newton meter (Nm).
• The turning effect of a force is called moment of a force, which is defined as the product of the force and the perpendicular distance from the pivot to the line of action of the force: m = f * d.
• The SI unit of moment is newton meter (Nm).
• Moment is a vector quantity that can turn either in clockwise or anticlockwise direction.
• A force applied in an upward direction will cause the plank to turn in an anti-clockwise direction above the pivot, creating an anti-clockwise moment.
• If there are more passengers at the upper level than the bottom level, the center of gravity of the double-decker will increase, making it less stable.
• Racing cars are designed to be low to increase their stability.
• The center of gravity can be moved by either putting more weight at the bottom of the object or making the object short or low, for example, a double decker.
• A force applied in an upward direction will cause the plank to turn in an anti-clockwise direction above the pivot, creating an anti-clockwise moment.
• If the number of passengers at the bottom level is more than the number of passengers at the upper level, the center of gravity of the double decker will be lower, making it more stable.
• Racing cars are designed to be low to increase their stability.
• The center of gravity can be moved by either putting more weight at the bottom of the object or making the object short or low, for example, a double decker.
• A force applied in a downward direction will cause the plank to turn in a clockwise direction above the pivot, creating a clockwise moment.
• To increase a greater moment, either more force or increased perpendicular distance can be applied.
• Turning a nut using a wrench, chopping vegetables using a knife, and cutting paper using a pair of scissors are examples of creating moments.
• Examples of turning effects include turning a nut using a wrench, chopping vegetables using a knife, and cutting paper using a pair of scissors.
• If both ranges are applied with the same force, the second diagram will create a greater moment, making it easier to turn the map.
• For an object to be in equilibrium state, the net external force must be zero, which obeys Newton's first law.
• If an external force is applied at one end of a plank, the plank will turn in an anticlockwise direction, and if another external force is applied at the other end, the plank will turn in a clockwise direction.
• An external force applied at one end of a plank will cause the plank to turn in an anticlockwise direction, and another external force applied at another end will cause the plank to turn in a clockwise direction.
• If the perpendicular distance between the two forces is equal and the magnitude of one force is equal to the magnitude of the other force, the net moment will be zero, but the moment in opposite direction will be different.
• The net moment about the pivot due to the external force must be zero.
• The handle of a wheelbarrow is long so that the effort is as far as possible from the pivot to produce the same amount of moment needed with smaller effort.
• The pivot of a wheelbarrow is located at the point where the load is applied, and the load produces its weight w.
• Applying the principle of moment, the wheelbarrow will turn in the direction of the clockwise moment, which is w times d1.
• For an anticlose moment, the wheelbarrow will turn in the direction of the counter-clockwise moment, which is f times d2.
• The resultant moment of the plank is determined by the principle of moment, and james needs to move to if they want the plank to be equilibrium.
• For an object to be considered in equilibrium, all forces acting on the object must be balanced and the resultant force is zero.
• A wheelbarrow is designed such that the load is as close as possible to the pivot to produce smaller moment.
• The effort f is the force applied to the wheelbarrow.
• A wheelbarrow is an example of an object that uses the principle of moment.
• The perpendicular distance d2 is the distance from the pivot to the point where the effort is applied.
• The authorized moment equals the total anticlockwise moment.
• The perpendicular distance d1 is the distance from the pivot to the point where the load is applied.
• If the perpendicular distance between the two forces is equal and the magnitude of one force is equal to the magnitude of the other force, the net moment will be zero, but the two forces will be in opposite directions.
• For an object to be considered in equilibrium, all forces acting on the object must be balanced and the resultant force is zero.
• The pivot of a wheelbarrow is located at the point where the load is applied, and the load produces its weight w.
• The Planck's principle states that for an object to be in equilibrium state, the sum of anticlockwise moments equals the sum of clockwise moments.
• For clockwise movement, the wheelbarrow will turn in this direction, hence clockwise moment will be w times d1.