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Give the answer in scientific notation:A human heart beats at an average of 80 beats per minute. How many times does it beat in(i) an hour?(ii) a day?(iii) a year?(iv) 100 years? |
Answer» Heart beat per minute = 80 beats (i) an hour One hour = 60 minutes Heart beat in an hour = 60 x 80 = 4800 = 4.8 x 10 (ii) In a day One day = 24 hours = 24 x 60 minutes ∴ Heart beat in one day = 24 x 60 x 80 = 24 x 4800 = 115200 = 1.152 x 105 (iii) a year One year = 365 days = 365 x 24 hours = 365 x 24 x 60 minutes ∴ Heart beats in a year = 365 x 24 x 60 x 80 = 42048000 = 4.2048 x 107 (iv) 100 years Heart beats in one year = 4.2048 x 107 Heart beats in 100 years = 4.2048 x 107 x 100 = 4.2048 x 107 x 102 = 4.2048 x 109 |
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