The weight could be different, metals have a higher mass than nonmetals, so when occupying the same amount of space, the weight of the metal is far more.
Answer:
balloon pushes you back
Explanation:
3rd Law: Every action has an equal and opposite reaction
So, when you let go of the balloon it's pushed forward so the balloon pushes you back
I think it is A. but then you can also produce your own energy
Answer:
Angular acceleration of the disk will be 
Explanation:
We have given mass of the disk m = 5 kg
Diameter of the disk d = 30 cm = 0.3 m
So radius 
Moment of inertia of disk is given by 
Force is given by F=4 N
Torque is given as 
We also know that torque is given by 

