math
posted by Lyn on .
An empty glass jar weighing 1.54 kg is in the shape of a cylinder which has a radius of 14cm and a height of 20cm. Calculate how many litres of water it will hold when filled to the top.Also calculate its weight when it is filled with water (take pie=22/7)

volume of jar =π(14^2(20) = 280π L
Since 1 L weighs 1 kg
the total weight is 280π + 1.54 = appr. 881.54
(The weight of 1 L of water is 1 Kg within 1/10000 of a kg, but since you are asked to use the rather clumsy value of 22/7 for π, we can go with that.
With the easy access to calculators, where the majority of them have π build in to about 7 digit accuracy, it surprises me that your text asks for 22/7 for π) 
the 280π is in cm^3 not litres.
so we have
288π/1000 + 4.54 = 2.45 kg