The average power is 10 watts. What's the question ?
Answer:
The mass of the cargo is 
Explanation:
From the question we are told that
The radius of the spherical balloon is 
The mass of the balloon is
The volume of the spherical balloon is mathematically represented as

substituting values


The total mass the balloon can lift is mathematically represented as

where
is the density of helium with a value of

and
is the density of air with a value of

substituting values


Now the mass of the cargo is mathematically evaluated as


Answer:
The speed of the 270g cart after the collision is 0.68m/s
Explanation:
Mass of air track cart (m1) = 320g
Initial velocity (u1) = 1.25m/s
Mass of stationary cart (m2) = 270g
Velocity after collision (V) = m1u1/(m1+m2) = 320×1.25/(320+270) = 400/590 = 0.68m/s
a the atom loses 1 proton to have a total of 34