The SI unit of force is:
J
N
m/s²
kg
A tennis racket is an example of a:
Class 1 lever
not a lever at all
Class 3 lever
Class 2 lever
A uniform metal rod AB, length 60 cm and weight 5 N, rotates about point A. A newton meter is attached at end B to balance the rod horizontally. What is the newton meter reading?
5 N
10 N
2.5 N
8 N
In a Class 1 lever, the fulcrum is located:
at the point where the effort is applied
outside the lever completely
at the point where the load is applied
between the effort and the load
If a force F acts on a body of mass m and gives it an acceleration a, what happens to the acceleration if the force is doubled while the mass stays the same?
a
2a
4a
a/2
Cruise Control in cars makes the forces acting on the car:
unbalanced
balanced
zero
multiplied
A person jumps from the front of a small boat and the boat moves backward. This is explained by:
Newton's Third Law
the law of gravitation
Newton's Second Law
Newton's First Law
Two forces of 30 N and 20 N act on a body along the same line of action in opposite directions. The resultant force equals:
25 N
50 N
0 N
According to Newton's Third Law, the action force and reaction force act on:
two different bodies
the same exact body
no at all physical body
more than two different bodies
The seat belt in a car works according to Newton's:
Second Law
First Law
Law of Universal Gravitation
Third Law
An airbag reduces the impact force on the driver by:
increasing the driver's speed just before impact
increasing the time of velocity change
stopping the car immediately upon collision
reducing the driver's mass during the collision
What is the magnitude of the resultant force needed to move a car of mass 1,200 kg with an acceleration of 3 m/s²?
1,200 N
400 N
3,000 N
3,600 N
The mechanical advantage (M.A.) of a lever equals:
effort × load
load ÷ effort
effort ÷ load
effort + load
Which of the following objects has the greatest inertia?
A locomotive of mass 2,000 kg moving at 30 m/s
A ball of mass 0.1 kg moving at 50 m/s
A runner of mass 70 kg moving at 30 m/s
A car of mass 1,000 kg moving at 50 m/s
The human head represents a:
Simple machines are tools that:
generate mechanical energy directly from the surrounding air
facilitate work and reduce effort, or change the direction of force
multiply the total amount of energy in a closed system
work automatically without needing any external force
When the electric current to a rotating fan is cut off, its blades continue to spin for a while due to
magnetism
air friction
gravity
inertia
A lever is a:
flexible rod that bends easily under heavy load
movable rod that works freely without any fulcrum
rigid rod that rotates about a fixed point
rod with complex internal gears and teeth
Newton's First Law is also known as:
The law of acceleration
The law of gravitation
The law of action and reaction
The law of inertia
When balanced forces act on a stationary body, the body:
remains stationary
accelerates
moves slowly
stops suddenly
Which of the objects X, Y, and Z below is subject to a non-zero resultant force?
X, Y, and Z
X only
Y only
Z and Y only
A lemon squeezer is an example of a:
A Class 3 lever does not provide mechanical advantage, but it:
only changes the direction of the applied force
increases the amount of applied force significantly
increases speed and extends the range of motion
reduces the total distance that the load travels
A drone (unmanned aerial vehicle) moves upward because:
the motors pull air upward in a direct manner
the downward push of air is matched by the air pushing the drone upward
gravity is reversed and points upward instead
the drone is lighter than the surrounding air
The law that explains how a rocket is launched in the direction opposite to the ejected burning gases is:
The Law of Universal Gravitation
When unbalanced forces act on a stationary body, the body moves in:
a completely random direction with no pattern
the direction opposite to the force
the direction of the resultant force
it does not move at all from its position
A resultant force of 1 N acts on a body of mass 1 kg. The acceleration produced is:
0.1 m/s²
1 m/s²
10 m/s²
100 m/s²
A lever is in equilibrium when:
the effort equals the load in magnitude
effort × effort arm = load × load arm
the effort moment is greater than the load moment
the effort arm equals the load arm
The bicep muscle (forearm) in the human body represents a:
A cargo cart accelerates less when it is:
heavily loaded with the same applied force
loaded with a greater applied force
empty with the same applied force
empty with a greater applied force
Two forces of 20 N act on a body in the same direction. The resultant force equals:
40 N
20 N
Newton's Second Law is expressed by the equation:
F = m × a
F = m + a
F = a / m
F = m / a
A tower crane (construction crane) belongs to:
simple machines
compound machines
rotary machines
Class 1 simple levers
Increasing the length of the effort arm in a lever leads to:
reducing the force needed to lift the same load
automatically reducing the length of the load arm
having no effect on the required lifting force
increasing the amount of force needed to lift the load
In an air-hockey experiment, the puck continues to move a long distance because:
friction between the puck and the table is reduced by the air layer
there is no gravity acting on the puck
the puck is very heavy and has high inertia
the applied force increases steadily with time
The Flyboard (water-propelled hoverboard) works on the principle of:
action and reaction
universal gravitation
balanced forces
Objects with greater mass have ______ inertia:
greater
smaller inertia than lighter objects
mass has no relation to inertia at all
the same inertia as smaller objects
When the mass of a moving body increases while the applied force remains constant, its acceleration:
becomes zero
decreases
increases
stays the same
Standing on tiptoes represents a:
A wheelbarrow is an example of a:
Class 4 lever
A Class 2 lever always provides mechanical advantage because:
the load arm is always longer than the effort arm
the effort arm is always longer than the load arm
the effort force and load force are always equal
the fulcrum is located exactly in the middle
If a car has a mass of 1,000 kg and a driving force of 1,300 N acts on it (ignoring other forces), its acceleration equals:
130 m/s²
0.13 m/s²
13 m/s²
1.3 m/s²
Passengers in a bus lurching forward when it brakes suddenly is explained by:
In a perfectly inelastic collision between a moving body and a stationary one of equal mass, the speed of each after the collision is:
the same speed as the moving body before the collision
zero immediately after the collision occurs
double the speed of the moving body before collision
half the speed of the moving body before the collision
A weight of 20 N is hung 15 cm to the right of the fulcrum, and a weight of 30 N is hung to the left at distance x. The value of x equals:
30 cm
20 cm
15 cm
10 cm
Inertia is the property of bodies to:
stop automatically
generate their own force
resist any change in their state of motion
change their speed quickly
In a Class 2 lever, the fulcrum is located:
between the effort and the load, with the effort between them
outside the lever and does not affect motion
always in the middle between effort and load
at one end of the lever, with the load between the fulcrum and the effort
A lever provides mechanical advantage (M.A. > 1) when:
the effort arm is longer than the load arm
both the effort arm and load arm are equal
the load arm is longer than the effort arm
there is no relation between the arms and MA
Pliers are an example of a:
A moving body collides with a stationary one of equal mass. The moving body stops and the stationary one moves at the same speed. This collision is:
inelastic
has no type
semi-elastic
elastic