Answer:
Electric field, 
Explanation:
It is given that,
Mass of sphere, m = 2.1 g = 0.0021 kg
Charge, 
We need to find the magnitude of electric field that balances the weight of a plastic spheres. So,

a = g



or

Hence, the magnitude of electric field that balances its weight is
. Hence, this is the required solution.
Answer:
The nearest plant (A) receives 4 times more radiation from the farthest plant
Explanation:
The energy emitted by the star is distributed on the surface of a sphere, whereby intensity received is the power emitted between the area of the sphere
I = P / A
P = I A
The area of the sphere is
A = 4π r²
Since the amount of radiation emitted by the star is constant, we can write this expression for the position of the two planets
P = I₁ A₁ = I₂ A₂
I₁ / I₂ = A₂ / A₁
Suppose index 1 corresponds to the nearest planet,
r2 = 2 r₁
I₁ / I₂ = r₁² / r₂²
I₁ / I₂ = r₁² / (2r₁)²
I₁ / I₂ = ¼
4 I₁ = I₂
The nearest plant (A) receives 4 times more radiation from the farthest plant
Answer: Government passing regulatory laws
Car emissions testing
Carpooling and less driving overall
Air pollution results when a mixture of particles and gases that can reach in harmful concentrations both outdoors as well as indoors. This increase in concentration can lead to rise in the temperatures and global warming it is also related with the health hazards. Soot, smoke, pollen, carbon dioxide, carbon monoxide and methane are the examples of the common pollutants.
Government passing regulatory laws: The government can ban some of the fossil fuels to prevent air pollution, and some vehicles which are likely to emit more partially combustible gases.
Car emission testing: Nowadays, cars and other vehicles are equipped with catalytic converters which converts the uncombustible gaseous products into less harmful gases which are emitted from the vehicle. The car gas emission testing should be performed to either allow a vehicle or ban the movement of the vehicle.
Carpooling and less driving overall: Carpooling is the sharing of one vehicle with more than one individual. This will prevent the need of others to drive another vehicle. The less the number of vehicles on the road the lesser will be the emission of gases and less pollution will be caused.
Answer:
upward force acting = 261.6 N
Explanation:
given,
mass of gibbon = 9.4 kg
arm length = 0.6 m
speed of the swing
net force must provide

force of gravity = - mg

= 
= 
=9 x 29.067
= 261.6 N
upward force acting = 261.6 N
The is organic compound with the correct chemical formula C4H9O2.
<h3>What is a model?</h3>
A model is a representation of reality. A model serves the purpose of prediction as well as explanation.
Looking at the model of the molecule we can see that it is the organic compound with the correct chemical formula C4H9O2. The molecule is shown in the image attached to this answer.
Missing parts:
There are several ways to model a compound. One type of model is shown.
What is the chemical formula for the molecule represented by the model?
CHO
C4H9O2
C4H8O
C3H8O2
Learn more about molecular models:brainly.com/question/156574?
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