Search our library of homework questions

Top answers

All subjects

All levels

An exoplanet of mass 1.36x10^26 kg is orbiting a star of mass 3.2x10^31 kg at a distance of 1 AU. What is the magnitude of the gravitational force between the two?

We use Newtons equation for gravitational force. F=GMm/r².1 AU is the mean distance at which the Earth orbits the Sun, taken to be: 1.49x10¹¹ m.Substituting in the numbers we find t...

Answered by Rory C. • Physics tutor

1691 Views

A bomb of mass 34kg, at rest is detonated. The explosion splits the bomb into two pieces, one of mass 13kg, which is thrown to the left at a velocity of 28 m/s. What is the velocity of the second piece?

In a collision where no external forces act linear momentum is conserved.Convention: Right + left -0=-13x28 + 21xVV=17.33 kg m/s to the right

Answered by Rory C. • Physics tutor

1434 Views

You have a five-litres jug, a three-litres jug, and unlimited supply of water. How would you come up with exactly four litres of water (with no measuring cup)?

You fill the 5-litres jug, and pour it into the 3-litres jug until it's full (now you have 2 litres in the 5-litres jug). Then, you pour out the 3-litres jug completely. Now, you pour the 2 litres from th...

Answered by Diana G. • Maths tutor

3959 Views

Given an unlimited number of light bulbs (that break at a certain height), and a building with 100 floors, how do you determine the height that the light bulb breaks?

The solution is a binary search algorithm (where you start on floor 50th and move up or down depending if the bulb breaks or not, always picking the middle floor of your option range).

Answered by Diana G. • Computing tutor

1431 Views

Personal Statement for English Literature

Huxley's Brave New World speaks to me of the necessity of the imagination, with its clinical eradication of individuality and the discontent that it breeds, through John Savage's understanding that hope l...

Answered by Harriet T. • Personal Statements tutor

1975 Views