Question

I. Multiple choice questions:
1. David wanted to measure how fast different insects can crawl. He must have a
ruler. What other tool does he need to use?
a) a clock with a second hand
b) a fan with different speeds
c) a long stick with a brush on the end
d) a thermometer with degrees Celsius​

Answer 1

Answer:

option a) clock with a second hand

Answer 2

the correct option will be (a) a clock with a second hand

• for measuring how fast the insect can crawl , parameters that need to be measured are as follows:

distance travelled by the insect

time taken by the insect to travel that distance.

• now since we have to measure how fast the insect crawls , this means we have to calculate the speed of the insect.

• so now in the process we will keep a ruler at a table and let the insect crawl. mark a random point at the ruler and note that distance. now observe the time taken by the insect to travel at that point.

• so now we have the distance travelled and the time taken . now calculate speed=distance/time . we will get the speed.

now coming to the options:

• (a) correct answer
• (b) fan provides air which is of no use here wrong
• (c) not required wrong
• (d) it measures the temperature and we don't require that wrong

now as david wants to measure how fast different insects can crawl then he must have a ruler and a clock with a second hand.

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