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Malaika haroon
Jul 19, 2014, 04:06 AM
A rectangular solid black of dimensions 20cm by 15cm by 10cm has a cylindrical hole bored through its centre. The mass of the block is now 14.9 kg and the material of the block has a density of 5gcm-3 . What is the cross-sectional area of the hole in cm2 ?

ebaines
Jul 19, 2014, 04:17 AM
This involves finding the volume of the solid block if it had no hole in it, and from that its mass. The difference between that and the actual mass of 14.9 Kg is due to the material missing because of the hole. Now determine the volume of the hole. Finally, you know the hole's depth (I assume there must be a picture that tells you which face of the block the hole is drilled through), so you can calculate its cross-sectional area. Try it, and post back with your answer.

Malaika haroon
Jul 19, 2014, 07:56 AM
The speed of the car is 35km/h. How far would it travel in 45 minutes?

ebaines
Jul 21, 2014, 05:30 AM
Please do not add a new question onto an old one, but start a new thread instead - which I see you have done here: https://www.askmehelpdesk.com/math-sciences/kinematics-797062.html