Top answers

How can you factorise expressions with power 3 or higher?

The key to factoring big and complicated expressions into simpler forms is to remember the factor theorem . The factor theorem says that if we plug a number k into our expression and it comes out as 0, then ...
CD
Answered by Christopher D. • Maths tutor
4615 Views

Why is the long-run Phillips Curve vertical?

The Phillips Curve depicts the relationship between unemployment and inflation. Suppose the government pursues an expansionary policy (e.g. lower interest rates). Using the classical model of aggregate deman...
FC
Answered by Fin C. • Economics tutor
29020 Views

What is the difference between Speed, Velocity and Acceleration?

Speed and Velocity are both measures of distance travelled in a given time and are therefore calculated using Speed=Distance/Time.Speed is a scalar quantity which means that it is quantified by a magnitude o...
Answered by • Physics tutor
11149 Views

Prove by contradiction that there is an infinite number of prime numbers.

The 'by contradiction' tells us we need to assume the opposite to begin with: 1) Let's assume there is a finite number of prime numbers2) Let P be the largest prime number (the last one) 3) if we multiply al...
CL
Answered by Charlotte L. • Maths tutor
20160 Views

Use the following data to explain why NaCl is soluble in water: ∆H = +31 kJmol-1, S(Na+(aq)) = 320.9 JK-1mol-1, S(Cl-(aq)) = 56.5 JK-1mol-1, S(NaCl(s)) = 72.1 JK-1mol-1 Are there any temperatures at which you would not expect NaCl to dissolve?

This is a nice simple calculation question which explores some basic thermodynamic principles and begins to apply them to simple reactions (in this case, solid salt dissolving in water) allowing predictions ...
KR
Answered by Kieran R. • Chemistry tutor
9099 Views