Page 41 - Science Class 6 Times Publication

d. Screw driver

i. Screw ii. Wedge
iii. Wheel and axle iv. Pulley

e. A Dhiki is a

i. First class lever ii. Second class lever
iii. Third class lever iv. None of these

2. Answer these questions in very short:
a. What is a simple machine ?

b. Why do we use simple machines ?

c. On what basis are the levers classied ?
d. What is a fulcrum ?

e. Why is crowbar a rst class lever ?
3. Dene the terms:

a. Pulley b. Single movable pulley
c. Wheel d. Axle

4. Give reasons:
a. We use tongs to catch a burning piece of a coal.

b. We use a pulley to draw water from a well.
c. A second class lever multiplies the effort more than other levers.

5. Differentiate between:

a. Pulley and wheel and axle.
b. Simple machine and complex machine

6. Classify the following levers:
crowbar, wheelbarrow, see-saw, nail-cutter, bottle opener,  re
tongs, beam balance, nut-cracker, shovel

Times' Crucial Science and Environment 37 Book 6