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Putting bee honey on a cut kills bacteria. Honey contains a high concentration of sugar. Use your knowledge of water potential to suggest how putting honey on a cut kills bacteria.

Once honey is added to an infected cut, the osmotic gradient favours water moving from the bacterial cells to the honey. This is because the water potential is lower in the honey. As a result of the loss ...

Answered by Harry M. • Biology tutor

3415 Views

Consider a cone of vertical height H (in metres) and base radius R (in metres) which is full with water. The cone, at time t=0, starts to leak such that it loses water at a rate of k m^3 per second. Give an expression for the rate of change of H.

L = (H²+R²)^1/2 V = (1/3)πR²(H²+R²)^1/2

dV/dt = -k

dH/dt = dH/dV × dv/dt

dV/dH = (1/3)πR²H(H^...

Answered by Callum E. • Maths tutor

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Integrate the following function: f(x) = ln(x)

∫ln(x)dx = xln(x) - ∫x/x dx = xln(x) - x + C

Answered by Callum E. • Maths tutor

3390 Views

Solve the simultaneous equations 3x+5y=7, 2x-3y=11

Multiply the first equation by 2, and the second by 3:

6x+10y=14

6x-9y=33

Subtract the second from the first:

19y=-19

solve for y:

y=-1

plug in to first eq...

Answered by Jamie B. • Maths tutor

9077 Views

Why is the differential of a constant zero?

Any constant (say k) can be rewritten as kx⁰ since x⁰=1. When you differentiate this, the 0 which is the power of the x term gets dragged to the front and is multiplied with the rest...

Answered by Jawad C. • Maths tutor

3527 Views