The driving thrust of the car produced by the engine is the main forward force.
The main opposing forces are air resistance (from the wind) and friction (between the tyres and the road)
Since the air resistance + friction = driving force the car moves at a constant speed.
I believe it's answer #3. Logically, at least.
You can test #1 through trial and error.
You can experiment #2 also through trial and error.
You cannot test #3 through trial and error, because that would be catastrophic.
You can test #4 through a survey and individual study and data collection.
Polar bonds are formed between atoms of different electronegativities.
<span>An exothermic reaction is one in which there is the production of heat whereas an endothermic reaction is one in which heat is absorbed. For the choices above, the answer would be letter B. Ice melting in water and an ice pack turning cold absorbs heat which is why it is an endothermic reaction. Exploding fireworks and gasoline burning gives off heat which is why it is an exothermic reaction.</span>
Since water has a density of about 1g/mL, and we are assuming HCl and NaOH are mostly water, the total mass of the 2 solutions is 100 g.
Due to the conservation of mass, the mass of product must equal the total mass of reactant, therefore the final mass must also be 100 g.