Answer:
This question is asking to identify the following variables:
Independent variable (IV): Battery
Dependent variable (DV): Time the clock stopped
Constant: Same clock
Control: No stated control
Explanation:
The independent variable in an experiment is the variable that is subject to manipulation or change by the experimenter. In this experiment, the independent variable is the BATTERIES (Duracell, Energizer, Kroger brand, EverReady).
The dependent variable is the variable that responds to the changes made to the independent variable. It is the variable that the experimenter measures. In this case, the dependent variable is the TIME IT TAKES FOR THE CLOCK TO STOP.
Constants or control variable is the variable that the experimenter keeps constant or unchanged for all groups throughout the experiment in order not to influence the outcome of the experiment. The constant in this case is the SAME CLOCK USED.
Control group is the group that does not receive the experimental treatment or independent variable in an experiment. In this case, all groups received a different kind of battery.
It would be 12,000 because newton’s third 2nd law states F=ma (force=matter x acceleration) so 30x400 would be your force .
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There is a repulsive force between two charged objects when they are of like charges/ they are likely charged (like charges repel each other)
Answer:
a) t=24s
b) number of oscillations= 11
Explanation:
In case of a damped simple harmonic oscillator the equation of motion is
m(d²x/dt²)+b(dx/dt)+kx=0
Therefore on solving the above differential equation we get,
x(t)=A₀
where A(t)=A₀
A₀ is the amplitude at t=0 and
is the angular frequency of damped SHM, which is given by,

Now coming to the problem,
Given: m=1.2 kg
k=9.8 N/m
b=210 g/s= 0.21 kg/s
A₀=13 cm
a) A(t)=A₀/8
⇒A₀
=A₀/8
⇒
applying logarithm on both sides
⇒
⇒
substituting the values

b) 

, where
is time period of damped SHM
⇒
let
be number of oscillations made
then, 
⇒
Rainbows are caused by the dispersion of light, which itself consists of a combination of refraction and reflection of light around little droplets of water.
Choice C