Search our library of homework questions

Top answers

All subjects

All levels

Explain how capillaries are adapted to their function of exchanging substances, giving 3 examples.

Firstly, capillaries are one cell thick and so this makes them very thin. This reduces the diffusion pathway between the capillary and other cells thus allowing efficient diffusion. Secondly, capillaries ...

Answered by Rebecca C. • Biology tutor

16264 Views

An amino acid contains 52.2% carbon, 9.3% hydrogen, 8.7% nitrogen and 29.8% oxygen by mass and has a relative molecular mass of 161 g/mol. What is its molecular formula? What functional groups must it have?

In 100g of compound, the amount of each element is given by: C: n = 52.2/12 = 4.35 H: n = 9.3/1 = 9.3 N: n = 8.7/14 = 0.621... O: n = 29.8/16 = 1.8625 Dividing through by the smallest amount (0.621) gives...

Answered by Georgina B. • Chemistry tutor

2605 Views

A ball of mass 500g is dropped from rest 2m above the ground. When it reaches the ground it is travelling at 5m/s. How much energy has been dissipated?

Initial energy (Gravitational Potential): E = mgh = 0.5 x 9.81 x 2 = 9.81J Final energy (Kinetic): E = mv²/2 = (0.5 x 5²)/2 = 6.25J Energy lost = 9.81 - 6.25 = 3.56J

Answered by Georgina B. • Physics tutor

1765 Views

Prove that the square of an odd number is always 1 more than a multiple of 4

(2x-1)² = 4x²- 4x + 1= 4(x²-x)+1The part of the expression which is: 4(x²-x) indicates that the value is a multiple of 4. The number 1 is then added which means...

Answered by Gokul P. • Maths tutor

2914 Views