Forces
This is the force that acts opposite of motion
Friction
A scalar quantity has ______________
size or magnitude only
WHat does equilibrium means
At rest and not moving
What is the formula for moments of a force?
T= Fxd
What are the three parts of lever?
fulcrum, load, effort
This is the type of foce that is dependent on other forces in order to create motion
push/pull or applied forcr
. Two forces of 8 N and 10 N CANNOT give a resultant of
(A) 1 N
(B) 2 N
(C) 9 N
(D) 18 N
A. 1
State what is missing in the formula below:
F1 x ___=____x d2
d1 and F2
A force of 200N acts at a perpendicular distance of 3m from a pivot. Find the moment of the force
600Nm
Where is the fulcrum for a first class lever
Between the effort and the load
This is the force that exists once objects are being stretched.
Tension
Identify all the vector quantities from below:
Mass, Direction, Time, Force, Displacement
Mass, Time
The __________________________________ of moments states that when a body is in equilibrium the sum of the _______________________________ about any ___________________ is equal to the sum of the
Principle , clockwise moments, point
A boy sits on one side of the see saw with a downward force of 550N. The weight at the centre of the see-saw is 300N. What is the Reaction force on the seew-saw
Sum of downward force= 550+ 300N
Thus the upward force is 850N
where is the load in a second class lever?
In the middle
This is the type of force every single object on Earth experiences every day
What is the pull of gravity
A 400N force acts east and a 500N force acts north. Find the magnitude of the resultant force.
640.3
State the two conditions that must be met when a body is in equilibrium,
1.The sum of the clockwise moments anout any point is equal to the anticlockwise moments.
2. Sum of the downward forces is equal to the sum of the upward forces.
A force of 300N is applied 4m from a turning point. Find the moment produced.
T=Fxd
300Nx 4m=1200Nm
A crowbar is used to lift a heavy stone. The crowbar is an example of a force multipier because?
A. Increases the speed of the effort
B. Changes the direction of the force only
C. Allows a small effort to lift a large load
D. Reduces friction between surfaces
C. Allows small effort to lift a large load
This is the force that works in the opposite direction of gravity
Upthrust/ Normal Force
A boat is pulled by two ropes. One rope pulls with a force of 400N east and the other pulls with a force of 500N west. Find the resultant force.
R= 500-400= 100N
Explain it is not advisable for a person to stand in a boat on water.
Standing makes it less stable. It raises the center of gravity so the boat can tip over easily.
A uniform metre rule is balanced on a pivot. A 200N force acts 2m to the left of the pivot. How far from the pivot must a 500N force act on the right side to keep the metre rule balanced?
Fxd=Fxd
200x 2= 500 xd
400Nm=500d
d=400/500
d=0.8m
A wheelbarrow is an example of a force multiplier because it allows.
A. a small effort to move a large load
B. the load to move faster than the effort
C. the effort to act in the same direction as the load
D. energy to be created by the machine.
A. A small effort to move a large load.