Tim has a weight of 500N, which his half of his father's weight. He, his father and his uncle sit on a see saw. If
both Tim and his father sit on the right ended of the
see saw, 5m from the pivot, his uncle's weight is the
same his fathers. Where should Tim's uncle sit in order
to achieve a state of balance?

3.75m on the left end

Explanation:

Given data

Tim's  weight = 500N= 0.5kN

Tim's fathers weight= 500*2= 1000N= 1kN

Tim and the fathers weight = 500+1000= 1500N= 1.5kN

Tim's uncle weight= 1.5kN

Length of seesaw= 5m

let the distance  Tim's uncle sits be x

We know that summation of clockwise moment equals the summation of anticlockwise moment

Taking moment about the center of the seesaw

1.5*2.5= 1*x

3.75= 1x

Divide boths sides by 1

x= 3.75/1

x= 3.75m

Hence Tim's uncle will sit 3.75m on the left end

i think it'll be 7,000

two charges are fixed in place on the x-axis as shown. the charge at x = 0 is negative and has magnitude q = 2 μcoulombs (1 μcoulomb = 10-6 coulombs). the charge at x = d, (d = +12 cm), is positive and has magnitude q = 4 μcoulombs. find a point x = xo along the x-axis at which the electric field is zero.