Search our library of homework questions

Top answers

All subjects

All levels

During sampling, discuss the principles and strategies that should be employed in the collection of representative samples.

First it is important to define a representative sample. A representative sample should have a mean very close to the entire population being sampled, i.e. you are able to account for the natural variatio...

Answered by Rowan S. • Biology tutor

5679 Views

How can there be both molecular and non-molecular solids?

Non-molecular solids are of the type of metallic and ionic solids. They are held together by the strong electrostatic interactions of polar particles like ions and electrons. For example in metals the str...

Answered by Gregory P. • Chemistry tutor

5989 Views

How do you work out the work out the current through resistors in parallel?

[I would use the whiteboard to draw diagrams as I was talking]
A good analogy for circuits is that of water pipes. The wires are nice wide pipes with no resistance to flow. Resistors are sections of ...

Answered by • Physics tutor

1646 Views

Why will antibiotics not cure the flu? Why should they not be overused?

The Flu is caused by the Rhinovirus. Antibiotics can only kill bacteria not viruses as viruses have different machinery to survive and replicate. Antibiotics have nothing to target in Viruses. Overuse of...

Answered by • Biology tutor

2220 Views

A cannon at ground level is firing at a fort 200m away with 20m high walls. It aims at an angle 30 degrees above the horizontal and fires cannonballs at 50m/s. Assuming no air resistance, will the cannonballs fall short, hit the walls or enter the fort?

solving horizontally, use v=s/t, where s=200, v=25(3)^1/2. Hence t=s/v=8/(3)^1/2 (where t is the time when the ball would reach the fort if it does not reach the ground)Solivng vertica...

Answered by • Maths tutor

2783 Views