Answer:
35 km/hr
Explanation:
Average speed = (total of the speed)/(the sets of speeds given)
Direction does not matter in this instance since speed is only magnitude,
Average speed = (30 + 40)/2
Average speed = 70 ÷ 2
= 35 km/hr
C₂H₃O₂⁻ is an anion.
<u>Explanation:</u>
NaC₂H₃O₂(s) → Na⁺(aq) + C₂H₃O₂⁻(aq)
NaC₂H₃O₂ when dissociated, yields Na⁺ and C₂H₃O₂⁻.
Anion is a negatively charged ion.
In this case, C₂H₃O₂⁻ is an anion.
Answer:
50
Explanation:
The mechanical advantage of a machine is given by

where
is the output force
is the input force
For the crowbar in this problem,
is the force in input applied by the worker
is the force that the machine must apply in output to overcome the resistance of the window and to open it
Substituting into the equation, we find

Answer:
The magnitude of the electric force between the to protons will be 57.536 N.
Explanation:
We can use Coulomb's law to find out the force, in scalar form, will be:
.
Now, making the substitutions
,
,
,
we can find:
.
.
Not so big for everyday life, but enormous for subatomic particles.
Answer:
Power = 124.50 W
Explanation:
Given that:
The Sound intensity of a speaker output is 102 dB
and the distance r = 25 m
For the intensity of sound,

where;
the threshold of hearing 



I = 0.01585 W/m²
If we recall, we know remember that ;
Power = Intensity × A
rea
Power = 0.01585 W/m² × 4 × 3.142 × (25 m)²
Power = 124.50 W