The baking soda looked like it dissolved in the vinegar. Sarah and Connor watched as the balloon expanded and filled with a gas.
2 answers:
Answer: A) chemical - gas produced
Explanation: Physical change is a process in which there is no change in chemical composition of the substance.
Chemical change is a process in which there is a change in chemical composition of the substance.
Chemical process is accompanied by following changes
1. Change in color
2. Absorption or release of energy
3. Production of gas
4. Formation of precipitates.
Thus a chemical reaction is happening on mixing baking soda and vinegar
, there is production of
which expanded the balloon.
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Answer:
time taken with speed 23 km/h will be 1.8 hours or 1 hour 48 minutes
Explanation:
Given:
Time is inversely proportional to the speed
mathematically,
t ∝ (1/r)
let the proportionality constant be 'k'
thus,
t = k/r
therefore, for case 1
time = 3 hr
speed = 14 km/hr
3 = k/14
also,
for case 2
let the time be = t
r = 23 km/h
thus,
we have
t = k/23
on dividing equation 2 by 1
we get
or
or
t = 1.8 hr = or 1 hour 48 minutes ( 0.8 hours × 60 minutes/hour = 48 minutes)
Solution :
Given :
Rectangular wingspan
Length,L = 17.5 m
Chord, c = 3 m
Free stream velocity of flow, = 200 m/s
Given that the flow is laminar.
So boundary layer thickness,
= 0.0024 m
The dynamic pressure,
The skin friction drag co-efficient is given by
= 0.00021
= 270 N
Therefore the net drag = 270 x 2
= 540 N