P6 Science

Tianzhu09 SG

Thank you for your help

Q1) Respiratory Systems

Under respiratory systems, there are two popular types of questions concerning the increase in breathing rates and heartbeat while doing exercises. What is the most appropriate information to put in while answering these types of questions?

Q1) After playing basketball with his friends, Tom checked his breathing rate again. He found that his breathing rate was 20 breaths per minute. Why was his breathing rate higher?

Q2) Jerry ran around the track for 20 minutes.
(a) What would happen to his heartbeat after 20 minutes? (b)Why is this so?

Q2) Chestnuts roasting on an open fire

Many love roasted chestnuts. While passing around stalls in the heartlands, the fragrant smell is simply tempting. Each merchant would stir their wok constantly, mixing chestnuts with tiny pebbles.

While waiting for these chestnuts to be cooked to perfection, spare some thoughts on why we need to roast chestnuts with tiny pebbles? Why can’t we cook chestnuts in a wok without tiny pebbles?

Please help to explain using information within Primary Science syllabus.

syncopation_music SG

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Q1 -the increase in breathing is allow the lung to get more oxygen ,and the heart pump up faster to remove carbon dioxide

Q2 the same as Q2

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Many love roasted chestnuts. While passing around stalls in the heartlands, the fragrant smell is simply tempting. Each merchant would stir their wok constantly, mixing chestnuts with tiny pebbles.

While waiting for these chestnuts to be cooked to perfection, spare some thoughts on why we need to roast chestnuts with tiny pebbles? Why can’t we cook chestnuts in a wok without tiny pebbles?

Pebbles is a good conductor of heat , it helps to heat up the chestnut more evenly