Is this a multiple answer?
<u>Answer:</u> The force that must be applied is 15 N.
<u>Explanation:</u>
Force exerted on the object is defined as the product of mass of the object and the acceleration of the object.
Mathematically,
where,
F = force exerted = ?
m = mass of the object = 3 kg
a = acceleration of the object = 
Putting values in above equation, we get:
Hence, the force that must be applied is 15 N.
We can explain this in a molecular level. We know that the difference between a gas and a liquid of the same composition is how fast their molecules are moving. So given a gas, their molecules are farther and faster when moving, but when they are cooled their bulk kinetic energy decreases. In other words their molecules start to move closer and move slower until it behaves more like a liquid molecule. This is the time when gases condense.
Answer:
They conducted it from earth
Explanation:
There had never been anything capable of observing it from space launched at that time because Sputnik wasn't even launched
Answer:
B) the chemicals are gaining energy from the surroundings.
Explanation:
The positive sign of the energy difference in a chemical reaction would indicate that the chemicals are gaining energy from the surroundings. This is what happens in an endothermic reaction.
In an endothermic reaction, heat is absorbed from the surroundings hence the surrounding becomes colder at the end of the changes.
- Here the energy change is assigned a positive value.
- This is because the heat energy level of the final state is higher than that of the initial state.
- So, the difference gives a positive value.
