Answer:

Explanation:
The volume of the balloon can be find compared the force in each cases so:
reduce 25% from 74kg

So the net force uproad on the balloon is

Now the density of the both gases air and helium are different however the volume is the same change offcorss the mass so:






Answer:
m = 77.75 g
Explanation:
Here we know that at equilibrium the temperature of the system will be 10 degree C
so heat given by hot latte = heat absorbed by the ice
now we have
heat given by latte = 


now heat absorbed by ice is given as



now by heat balance we have



Answer:
(c) 97 dB sound intensity level
Explanation:
We have given the intensity of the loud car horn 
We know that 
Now the sound intensity level is given by
, which is nearly equal to 97
So the sound intensity level will be 97 dB
So option (c) will be the correct option