#1
Which of the following is a unit of work?
Joule
ExplanationJoule is the SI unit of work.
#2
Which of the following is a form of potential energy?
Gravitational energy
ExplanationGravitational energy is a type of potential energy.
#3
What is the relationship between work and energy?
Energy is a form of work
ExplanationEnergy can be seen as the ability to do work.
#4
What is the unit of measurement for power?
Watt
ExplanationWatt is the SI unit of power.
#5
What is the SI unit of work?
Joule
ExplanationJoule is the SI unit of work.
#6
What is the work done when a force of 20 Newtons is exerted on an object over a distance of 5 meters?
4 Joules
ExplanationWork is calculated by multiplying force and displacement, hence 20N * 5m = 100 J.
#7
Which of the following is an example of a second-class lever?
Wheelbarrow
ExplanationA wheelbarrow is a classic example of a second-class lever.
#8
What is the formula for calculating kinetic energy?
KE = 1/2 mv^2
ExplanationKinetic energy is calculated using the formula KE = 1/2 mv^2.
#9
Which of the following is an example of a third-class lever?
Fishing rod
ExplanationA fishing rod exemplifies a third-class lever.
#10
Which of the following statements about simple machines is true?
They can multiply force but not energy
ExplanationSimple machines enable the multiplication of force while conserving energy.
#11
A machine lifts a load of 500 N with an effort of 100 N. What is the mechanical advantage of the machine?
2
ExplanationMechanical advantage is calculated as load force divided by effort force, hence 500N / 100N = 5.
#12
In the absence of air resistance, what happens to the mechanical energy of a swinging pendulum?
It remains constant
ExplanationMechanical energy, the sum of potential and kinetic energy, is conserved in the absence of external forces like air resistance.
#13
What is the efficiency of a machine that does 150 J of work output while 200 J of work input is applied to it?
0.75
ExplanationEfficiency is calculated as work output divided by work input, hence 150J / 200J = 0.75.
#14
What is the law of conservation of energy?
Energy cannot be created or destroyed, only transformed
ExplanationThe law of conservation of energy states that energy cannot be created or destroyed, only changed in form.
#15
Which of the following statements about energy is true?
Energy is always conserved in any process
ExplanationEnergy is conserved in all processes according to the law of conservation of energy.