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A triangle has sides A, B and C. The side BC has length 20cm, the angle ABC is 50 deg and angle BAC is 68 deg. a) Show that the length of AC is 16.5cm, correct to three significant figures. b) The midpoint of BC is M, hence find the length of AM

a) The answer to this question is quite simple, it is all dependent on the pupil realising that they need to use the sine rule. This rule for this triangle is: BC/sin(BAC) = AC/sin(ABC) Once they get this eq...
RS
Answered by Ravi S. • Maths tutor
5794 Views

What is meant by the "fluid-mosaic" model of cell membrane structure?

The cell membrane consists of a double layer of phospholipids, with proteins floating in it. Phospholipids are a type of molecule with a phosphate head, and fatty tails, which form a double layer around the ...
HH
Answered by Harriet H. • Biology tutor
30041 Views

How do I find the inverse of a 2x2 matrix?

Hiya! So the very first thing we need to do is find the determinant, which is just a fancy word to describe a matrix; for a 2x2 matrix, it's equal to "ad-bc", where: (a b c d) This will give you a ...
NC
Answered by Namir C. • Maths tutor
6084 Views

A DVD is dropped from rest. The DVD does not reach terminal velocity before it hits the ground. Explain how the acceleration of the DVD varies from the instant it is dropped until just before it hits the ground.

In the instant when the DVD is dropped, it will have an acceleration of g, with no drag force acting on it as it is not moving. As the DVD accelerates downwards, the drag force acting on it increases and so ...
DH
Answered by Dylan H. • Physics tutor
4465 Views

A kettle is found to output 65J when its input energy is 100J. What is the efficiency of the kettle, and what happens to the rest of the energy?

Efficiency=useful energy /input energy x 100, so for the kettle, efficiency = 65/100 x 100 = 65% efficient. The rest of the energy is wasted as heat energy in the kettle/sound energy.
JL
Answered by Joshua L. • Physics tutor
22996 Views