Work and Energy ( Term 1 Chapter 3 | 4th Science )
Evaluation
I. Use the correct
word to fill the blanks.
(Ramp, Simple machines, Work, Energy, Pulley)
1. Work
is said to be done when a force is acting on it.
2. The ability to do work is Energy .
3. Pulley
is a machine made up of wheel and rope.
4. Simple
Machine help us to make work easier.
5. An example for inclined plane
is Ramp.
II. Rearrange the
letters and find out the names of the tools.
EDGEW RLEVE EWCRS
III. Match.
1. Class II lever - Drawing water
2. Pulley - Bicycle
3. Class I lever - Nut cracker
4. Wheel and axle - Wind
5. Renewable resource – Seesaw
Answer:
1. Class II lever -
Nut cracker
2. Pulley - Drawing
water
3. Class I lever - Seesaw
4. Wheel and axle -
Bicycle
5. Renewable
resource - Wind
IV. Classify the things below.
Class of Lever
1. Spade : III
2. Seesaw : I
3. Wheel barrow : II
4. Plier : III
5. Nail cutter : III
V. Answer the
following.
1. What is the unit of energy?
The unit of energy is Joule.
2. Name some simple machines.
The pulley, wedge, inclined plane, screw, lever,
wheel and axle are some simple machines.
3. What is a first order lever?
When the fulcrum is between the effort and the load
it is known as a first order lever.
4. Lemon juicer belongs to which
type of lever? Why?
Lemon juicer belongs to class II lever because the
load (lemon) is between effort and fulcrum.
5. Define work.
An action in which one exerts force to more an
object is known as work.
6. Write any three types of
energy.
Chemical energy, electrical energy, thermal energy.
Think and say
Teacher: Yesterday I was walking back from school. I found some people working to lay the road. I found some items in that place. Can you say something about that place and the machines that were used there? Or
Say something about the machines that were used. When can we say that work is done or not?
Answer: Machines like road roller, crow bars, spades, pick axe and shovels are used. The shape of the road is changed by applying force. So we say that work is done.
Try to Answer
Observe the picture and put a tick (✓) if work is done and put a cross (x) if work is not done.
Try to Answer
Mention whether work is done or not in the following activity.
Observe the picture. Which is easier? Lifting the load with the help of a pulley or without a pulley?
Answer: Lifting the load with the help of a pulley is easier.
Observe the picture and discuss. Is lifting a box is easier than rolling it on a ramp?
Answer: Rolling a box on a ramp is easier than lifting it.
Try to Answer
Identify and mention the types of simple machines.
Try to Answer
Complete the table.
1. Pulley: To draw water from wells
2. Wheel and axle: To drive a bicycle
3. Wedge: To split materials
4. Inclined plane: Rolling things up or down
5. Lever: To increase the force given
6. Screw: To hold objects together
Try to Answer
Name the load, effort and fulcrum.
Related Topics
Privacy Policy, Terms and Conditions, DMCA Policy and Compliant
Copyright © 2018-2024 BrainKart.com; All Rights Reserved. Developed by Therithal info, Chennai.