Search our library of homework questions

Top answers

All subjects

All levels

Explain the role of the moderator in a fission reaction.

slows neutrons/reduces KE of neutrons so that neutrons can be absorbed by the U-235 nucleus to cause fission to release kinetic energy. (nuclear reactor and energy)

Answered by Rishi J. • Physics tutor

2657 Views

A ball in a room is thrown with a speed v = 15 m/s at an angle 45 degrees above the horizontal. If the ceiling is 4 m high, will the ball hit the ceiling? If so, what is the minimum angle at which the ball will not hit the ceiling? Neglect air resistance.

Since we want to find the height reached by the ball, we only want to consider the vertical component of the ball's velocity. Using trigonometry, the y component will be:
v_y= 15 * sin (45)...

Answered by Hiro F. • Physics tutor

1963 Views

Explain what is meant by specific latent heat of fusion

Specific latent heat of fusion is the energy (required) to change 1 kg / unit mass of material from the solid state to the liquid state or melt/fuse 

Answered by Rishi J. • Physics tutor

8820 Views

Find the two real roots of the equation x^4 -5=4x^2 Give the roots in an exact form.

Disguised quadratic. Let y=x^2So quadratic become y^2-4y-5=0so (y-5)(y+1)=0so y=5 and y=-1so x^2 = 5 or -1cannot be -1 as not real henso x^2=5x=+-sqrt(5)

Answered by Rishi J. • Maths tutor

3724 Views

The straight line L1 passes through the points with coordinates (4, 6) and (12, 2) The straight line L2 passes through the origin and has gradient -3. The lines L1 and L2 intersect at point P. Find the coordinates of P.

Find equation of line 1 in terms of x. eg y=mx+c - Using gradient and points. Equation of line 2 is just y=-3xSo -3x=mx+c of line 1Find xSub into one equation to find the y point.Done

Answered by Rishi J. • Maths tutor

10053 Views