The expected speed is v = 85.5 km/h
v = 85.5 km/h = (85.5 km/h)*(0.2778 (m/s)/(km/h)) = 23.75 m/s
If there is an uncertainty of 2 meters in measuring the position, then within a 1-second time interval:
The lower measurement for the speed is v₁ = 21.75 m/s,
The upper measurement for the speed is v₂ = 25.75 m/s.
The range of variation is
Δv = v₂ - v₁ = 4 m/s
The uncertainty in measuring the speed is
Δv/v = 4/23.75 = 0.1684 = 16.84%
Answer: 16.8%
Answer: Hydrogen gas will be given off
Explanation:
Whenever a metal reacts with an acid, a salt of the metal is formed and hydrogen gas is given off.
For instance: The reaction of Zinc metal on Hydrochloric acid.
Zn(s) + 2HCl(aq) ---> ZnCl2(aq) + H2(g)
From the equation provided, hydrogen gas is given off as a by-product