2. Predict what will happen if the 80 kg adult was further from the pivot (more right) and explain your reasoning. 3. Predict what will happen if the 30 kg child was closer to the pivot (more right) and explain your reasoning. 4. Test your predictions in the Balance Lab. Make notes about any ideas you have that need to be changed. 5. What are some rules you could use to make predictions for other situations where masses are on a balance

2) τ = F x  torque increases, 3) troque decreases,

4)  man approaches the pivot and the child must move away

5)  Σ τ = 0

Explanation:

2) when the man moves away from the pivot his torque increases significantly, since his distance increases

                 τ = F x

                 τ = m g x

therefore the system rotates faster

3) when the child approaches the pivot, his troque decreases, because the distance decreases

                 τ = f x

therefore the system must spin slower

4) If we place the man and the child on the side of a scale, the movement must be the man approaches the pivot and the child must move away, so that the torque is the same and the system can reach a balance

5) the rotational equilibrium expression

                 Σ τ = 0

is the one that describes the equilibrium of a system with several forces

when it gains or loses electrons

answer: 2×10^-2kg

explanation: density= mass per volume

vol=mass/density

converting to s.i units we have;

3÷1000kg = 0.003

1.5÷100m = 0.15

0.003/0.15 = 0.02kg