A spherical hot air balloon of diameter 20. meters just floats ...

[humphriesbr@me.com]

A spherical hot air balloon of diameter 20. meters just floats (hovers) when the hot air inside has been heated to a density of 1.00 kg/m3.
 
  What is the weight of the balloon and cargo (not including the air inside) if the surrounding air has a density of 1.30 kg/m3?

Question 2

A charged particle moves with a constant speed through a region where a uniform magnetic field is present. If the magnetic field points straight upward, the magnetic force acting on this particle will be maximum when the particle moves
 
  A) upward at an angle of 45 above the horizontal.
  B) straight upward.
  C) straight downward.
  D) horizontally.

[jamesnevil303]

Answer to Question 1

1.2  104 Newtons (weight of 1.3  103 kg)

Answer to Question 2

D

[humphriesbr@me.com]

TYSM

[lcapri7]

Thanks for the timely response, appreciate it