Scientific knowledge is built as people come up with hypotheses and theories, repeatedly check them against observations of the natural world and continue to refine those explanations based on new ideas and observations.
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:
B. 2K + Br2 + 2KBr
D. C + 02 → CO2
Explanation:
In balancing a chemical reaction, the number of atoms on both sides of the expression must be the same in order to obey the law of conservation of mass.
According to the law of conservation of mass, in a chemical reaction, matter is neither created nor destroyed.
So, let us investigate:
Number of atoms
Reactants Products
K 2 2
Br 2 2
C + 0₂ → CO₂
C 1 1
O₂ 2 2
We see that for both equations, the number of atoms on both sides of the expression is the same.
Answer:
9.4 m/s
Explanation:
According to the work-energy theorem, the work done by external forces on a system is equal to the change in kinetic energy of the system.
Therefore we can write:
where in this case:
W = -36,733 J is the work done by the parachute (negative because it is opposite to the motion)
is the initial kinetic energy of the car
is the final kinetic energy
Solving,
The final kinetic energy of the car can be written as
where
m = 661 kg is its mass
v is its final speed
Solving for v,
