Question: What is force?
Answer: A push or pull acting on an object is called force.
Question: What is gravity?
Answer: The force that attracts objects towards the center of the earth is called gravity.
Question: What is magnetism?
Answer: The push or pull applied by a magnet on metals like iron and nickel and on other magnets is called magnetism.
Question: What is energy? Name any four types of energy.
Answer: The ability to do work is called energy. The four types of energy are heat energy, light energy, wind energy and sound energy.
Question: What is a machine?
Answer: A machine is a tool that makes our work easier by helping us overcome a larger force (load) by applying lesser force (effort).
Question: Name the six types of simple machines.
Answer: The six types of simple machines are:
- Wheel and axle
- Inclined plane
Question: List the four effects that force have on objects.
Answer: The four effects that force have on objects are:
- A force can make a stationary object move or make a moving object move faster.
- A force can make a moving object stop or slow down.
- a force can change the direction in which an object is moving.
- A force can change the shape of an object.
Question: What is friction? Why is friction necessary?
Answer: The force that tries to stop the sliding movement of objects across a surface is called friction. Friction is necessary because friction between or feet and ground makes it possible for us to walk.