Top answers

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 = mv 2 /2 = (0.5 x 5 2 )/2 = 6.25J Energy lost = 9.81 - 6.25 = 3.56J
GB
Answered by Georgina B. • Physics tutor
2477 Views

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

(2x-1) 2 = 4x 2 - 4x + 1= 4(x 2 -x)+1The part of the expression which is: 4(x 2 -x) indicates that the value is a multiple of 4. The number 1 is then added which means that the statement 'the square of an od...
GP
Answered by Gokul P. • Maths tutor
3669 Views

4y^2 = 256, Find a value for y

y^2 = 256/4 = 64 therefore, y = sqrt(64) = 8
KP
Answered by Kai P. • Maths tutor
3696 Views

A circle with centre C has equation x^2+8x+y^2-12y=12. The points P and Q lie on the circle. The origin is the midpoint of the chord PQ. Show that PQ has length nsqrt(3) , where n is an integer.

First complete the square for both x and y. Move all constants to the right hand side. The square root of this is the radius of the circle. The two constants in the completed square bracket show the x and y ...
Answered by • Maths tutor
9107 Views

Solve the simultaneous equations: 2x + y = 12; x - y = 6

We add the two equations together (left-hand sides and right-hand sides separately). By doing this we get: 2x + y + (x - y) = 12 + 6. By rearranging and simplifying: 3x = 18.If we divide both sides by 3 we g...
RD
Answered by Rebeka D. • Maths tutor
6925 Views