Answer:Gravity
Explanation:Gravity is the force that pulls everything down instead of up because if we didn’t have gravity we would be floating upwards
Answer: 
Explanation:
Given
Volume of air 
Temperature of air 
Increase in temperature 
Specific heat for diatomic gas is 
Energy required to increase the temperature is
![\Rightarrow Q=nC_pdT\\\\\Rightarrow Q=n\times \dfrac{7R}{2}\times \Delta T\\\\\Rightarrow Q=\dfrac{7}{2}nR\Delta T\\\\\Rightarrow Q=\dfrac{7}{2}\times \dfrac{PV}{T}\times \Delta T\quad [\text{using PV=nRT}]](https://tex.z-dn.net/?f=%5CRightarrow%20Q%3DnC_pdT%5C%5C%5C%5C%5CRightarrow%20Q%3Dn%5Ctimes%20%5Cdfrac%7B7R%7D%7B2%7D%5Ctimes%20%5CDelta%20T%5C%5C%5C%5C%5CRightarrow%20Q%3D%5Cdfrac%7B7%7D%7B2%7DnR%5CDelta%20T%5C%5C%5C%5C%5CRightarrow%20Q%3D%5Cdfrac%7B7%7D%7B2%7D%5Ctimes%20%5Cdfrac%7BPV%7D%7BT%7D%5Ctimes%20%5CDelta%20T%5Cquad%20%5B%5Ctext%7Busing%20PV%3DnRT%7D%5D)
Insert the values

The train is moving at 50 m/s and Emma is walking down the aisle with 1 m/s speed in the same direction of train. The relative velocity of Emma with respect to other passengers pf the train would be 1 m/s. This is because, the train is not moving relative to them and only emma is moving at 1 m/s. If a person observes from outside, Emma would have (50 +1) m/s = 51 m/s velocity.
relative velocity when two objects are moving in same direction as oberved from outside observer:

relative velocity when two objects are moving in the opposite directionas oberved from outside observer:

Answer:
I think it's a true but I'm not the smartest