Answer:
The distance from the pivot point that the small child will sit in order to maintain the balance is 1.8 m
Explanation:
Given;
mass of the bigger child, M = 30 kg
mass of the smaller child, m = 20 kg
distance between the two children, d = 3 m
This information can be represented diagrammatically;
3m
|<------------------------------------------------>|
----------------------------------------------------------------------------
↓ x Δ 3-x ↓
20kg 30kg
x is the distance from the pivot point that the small child will sit in order to maintain the balance
Take moment about the pivot;
Clockwise moment = anticlockwise moment
30(3-x) = 20x
90 -30x = 20x
90 = 20x + 30x
90 = 50x
x = 90 / 50
x = 1.8 m
Therefore, the distance from the pivot point that the small child will sit in order to maintain the balance is 1.8 m
Answer:
to help people breach in fresh air
Explanation:
Answer:
(a) Jx = -1.14Ns, Jy = 110×3×10-³ = 0.330Ns (b) V = (0m/s)ı^−(1.79m/s)ȷ^
Explanation:
Given
W = 0.56N = mg
m = 0.56/g = 0.56/9.8 = 0.057kg
t = 3.00ms = 3.00×10-³s
Impulse is a vector quantity so we would treat it as such
We have been given the force and velocity in their component forms so to get the impulse from these quantities, we pick the respective component for the quantity we want to calculate and do the necessary calculation. The masses are scalar quantities and so do not affect the signs used in the calculations whether positive or negative. So we have that
u = (20.0m/s)ı^−(4.0m/s)ȷ^
ux = 20m/s
uy = – 4.0m/s
F = – (380N)ı^+(110N)ȷ^
Fx = –380N
Fy = 110N
J = impulse = force × time = F×t
So Jx = Fx ×t
Jy = Fy×t
Jx = –380×3×10-³ = -1.14Ns
Jy = 110×3×10-³ = 0.330Ns
Impulse also equals the change in momentum of the body. So
J = m(v–u)
J/m = v – u
V= J/m + u
Vx = Jx/m + ux
Vx = –1.14/0.057 + 20
Vx = -20 + 20 = 0m/s
Vx = 0m/s
Vy= Jy/m + uy
Vy= 0.33/0.057 + (-4.0)
Vy= 5.79 + (-4.0) = 1.79m/s
V = (0m/s)ı^−(1.79m/s)ȷ^