Search our library of homework questions

Top answers

All subjects

All levels

Two particles A and B of mass 2kg and 3kg respectively are moving head on. A is moving at 5m/s and B is moving at 4m/s. After the collision, A rebounds at 4m/s. What is the speed of B and what direction is it moving in?

Using conservation of momentum, m1u1 + m2u2 = m1v1 + m2v2, set m1 = 2kg, m2 = 3kg, u1 = 5m/s, u2 = -4m/s and v1 = -4m/s. Substitute these into the equation to get 25 + 3(-4) = 2*(-4) + 3*v2 10 - ...

Answered by Amber S. • Maths tutor

4709 Views

An unknown capacitor is charged to 6v, its maximum value, then discharged through a 1k ohm resistor. If the capacitor voltage is 3v, 0.3 seconds after starting to discharge, what is the capacitance of the unknown capacitor?

To start, the equation to use can be identified as the capactior discharge equation V(t) = V_maxe^-t/RC. From here, we can see that this equation can be solved to give capacitance, and...

Answered by Alexander R. • Physics tutor

3080 Views

Calculate the pH change when water is added to 25.0 ml of 0.250M NaOH to form a 1.00l solution.

The initial [-OH] is 0.250M since NaOH releases 1 mole of -OH per mole of base. Using Kw=[H+][-OH], [H+]=(110^-14)/0.250=410^-14M (note remember units). Hence the initial pH=-...

Answered by Milind S. • Chemistry tutor

15340 Views

Describe the structure of a protein

All proteins are polymers of amino acids arranged with varying degrees of complexity. The most basic structure is the order of amino acids, this is called the primary structure. Amino acids form peptide b...

Answered by Sam C. • Biology tutor

3048 Views

Briefly explain how Darwin formulated his theory of evolution by natural selection.

Darwin made four key observations in his studies of wild populations: members of a population of the same species vary in their traits; traits can be inherited, or passed from parents to offspring; popula...

Answered by Zak L. • Biology tutor

2838 Views