<u>Answer:</u> The acceleration of the object is 2m/s^2. If net force increases, acceleration will also increase and if mass increases, the acceleration will decrease.
<u>Explanation:</u>
Force is defined as the product of object's mass and acceleration.
Mathematically,
F = ma ......(1)
or,
a = F/m .....(2)
where,
F = Force exerted on an object = 60N
m = mass of an object = 30kg
a = acceleration of the object = ?
Putting values in above equation, we get:
a = 60 kg.m/s^2/30 kg = 2m/s^2
The acceleration of the car is 2m/s^2.
From equation 2, it is visible that acceleration is directly proportional to force. This means that \if force increases, acceleration also increases.
And acceleration is inversely proportional to mass of the object. This means that if mass increases, the acceleration decreases.
Hence, if net force increases, acceleration will also increase and if mass increases, the acceleration will decrease.
Answer : The combustion is a process in which oxygen is released as a by-product of oxidation-reduction reactions.
Explanation :
Combustion reaction : It is defined as the reactions in which a hydrocarbon reacts with oxygen gas to produce carbon dioxide and water.
The chemical equation of combustion reaction is:

The combustion reaction is also a redox reaction.
Redox reaction or Oxidation-reduction reaction : It is defined as the reaction in which the oxidation and reduction reaction takes place simultaneously.
Oxidation reaction : It is defined as the reaction in which a substance looses its electrons. In this, oxidation state of an element increases. Or we can say that in oxidation, the loss of electrons takes place.
Reduction reaction : It is defined as the reaction in which a substance gains electrons. In this, oxidation state of an element decreases. Or we can say that in reduction, the gain of electrons takes place.
The combustion reaction is also a redox reaction in which the carbon shows oxidation by the addition of oxygen or removal of hydrogen and oxygen shows reduction by the addition of hydrogen or removal of oxygen.
Hence, the combustion is a process in which oxygen is released as a by-product of oxidation-reduction reactions.
<span>The metal also gives off heat in the form of radiation.
Just took the test and got it right, using a process of elimination based on what you know helps. Hope this helps!</span>