Answer:
Explanation:
1 ) the volume of helium in the balloon when fully inflated
= 4/3 π R³
= 4/3 x 3.14 x 5.3³
= 623.3 m³
2 ) force of gravity on the entire system ,but with no people
= (mass of the empty balloon and basket + mass of helium )x g
=( 129 + 623.3 x.18 )x 9.8
= 2363.7 N
3 ) magnitude of the buoyant force on the entire system (but with no people )
( Volume of empty balloon + basket + volume of helium ) density of air x g
( 0.057 + 623.3 ) x 1.23 x 9.8
= 7513.94 N
4 ) magnitude of the force of gravity on each person
Mass of each person x g
= 71 x 9.8
= 695.8 N
Answer:
The change in momentum is 
Explanation:
From the question we are told that
The time taken for the stone to stop is 
The net force on the rock is 
The impulse of the rock can be mathematically represented as

Substituting values


Now impulse is defined as the rate at which momentum change
Hence the change in momentum
of the rock is equal to the impulse of the rock
So

The steps in the heating of a metal seat in a park are:
Step 1: Heat travels from the sun to Earth
Step 2: Heat travels through atmosphere to the top of the seat
Step 3: Heat from the top of the seat travels through the seat to the lower parts of the seat.
-- Heat is transferred by radiation in Step 1 and Step 2. <em>(B)</em>
-- From the top of the seat to the bottom, heat is transferred by conduction.
There's no convection happening anywhere in the park-hot-seat scenario.
We need to consider no change in the temperature of gas (isothermal transformation)
Volume and pressure are inversely proportional magnitudes, so we can write: