4g of a radioactive material of half-life 10 days is spil...
4g of a radioactive material of half-life 10 days is spilled on a laboratory floor. How long would it take to disintegrate 3.5g of the material?
1\(\frac{1}{4}\) days
8\(\frac{1}{4}\) days
30 days
80 days
Correct answer is C
half-life = 10 days
after 10 days, the 4g of element = 2g remaining with 2g disintegrated
after 10 days, 2g of element = 1g left with 1g disintegrated
hence, after 20 days, 3g of the element has been disintegrated with 1g left.
after 10 days, the 1g of element = 0.5g left with 0.5g disintegrated
after 30 days, we have 0.5g of element left with 3.5g disintegrated.
A man weight 800N climbs up a stairs to height of 15m in 12.5s. What is the man''s average p...
A small object of mass 50 g is released from a point A. Determine the velocity of the object wh...
A bulb marked 240V, 40W is used for 30 minutes. Calculate the heat generated ...
A rectangular piece of iron measuring 4 cm by 3 cm at 20\(^o\)C is heated until its temperature...