Class 5 Science Question Answers - Work, Force, Energy and Simple Machines

Q1: What is force, and how does it relate to doing work?
Ans: Force is a push or pull applied to an object. It is needed to make things move, and when force is applied to move something, work is done.

Q2: Explain the different effects of force with examples.
Ans: Force can move a stationary object, make a moving object move faster, change the direction of a moving object, stop a moving object, and slow down a moving object when applied in the opposite direction. Examples include pushing a car, stopping a bicycle, or changing the direction of a ball by kicking it.

Q3: What are the different types of forces mentioned in the text, and provide examples of each.
Ans: The different types of forces are gravitational force (e.g., objects falling to the ground), magnetic force (e.g., magnets attracting iron), muscular force (e.g., pushing or pulling something), electrostatic force (e.g., charged materials attracting or repelling), and frictional force (e.g., stopping or slowing down objects when they're in contact).

Q4: What are the various forms of energy mentioned in the text, and how are they useful in our daily lives?
Ans: The various forms of energy include light energy (for seeing things), heat energy (from sources like the sun or burning fuels), sound energy (from devices and living things), electrical energy (used in appliances), and mechanical energy (due to an object's position or movement). These forms of energy are essential for various aspects of our daily lives.

Q5: Explain the concept of simple machines. How do they make work easier?
Ans: Simple machines are tools with a straightforward structure that make work easier and faster. They do this by either changing the direction of force or increasing force. Examples include levers, wheel and axle, inclined planes, wedges, screws, and pulleys.

Q6: Describe the three types of levers and provide examples of each.
Ans: The three types of levers are:

• Class 1 Lever: The fulcrum is between the load and the effort (e.g., a seesaw).
• Class 2 Lever: The load is between the fulcrum and effort (e.g., a wheelbarrow).
• Class 3 Lever: The effort is between the fulcrum and load (e.g., tweezers).

Q7: What is a wheel and axle? Give examples of wheel and axle devices.
Ans: A wheel and axle consist of a wheel attached to an axle. When the axle is turned, the wheel moves. Examples include the steering wheel of a car, a screwdriver, a sewing machine, and a doorknob.

Q8: Explain what an inclined plane is and provide examples of its use.
Ans: An inclined plane is a sloped surface where less effort is needed to move an object up compared to lifting it straight up. Examples include ramps, staircases, slides, and hilly roads.

Q9: What is a wedge, and how is it used as a simple machine?
Ans: A wedge is formed by two inclined planes joined back to back in the shape of a V. It has at least one slanting side ending in a sharp edge. Examples of wedges include nails, forks, knives, and axes.

Q10: What is a screw, and how does it increase force? Provide examples of screw devices.
Ans: A screw has grooves (threads) cut into it and is turned round and round with a screwdriver to insert it into objects. It increases force because it takes less effort to insert a screw than a nail. Examples include screw jacks, drilling machines, and nut bolts.