Answer:
a) 
b) 
Explanation:
Given the information from the exercise we can calculate the work done by the elevator using the following formula:

a) Considering you and your belongings as a system we know that the elevator is applying a Normal reaction force of:

Since the force applied and the displacement is in the same direction, the work done by the elevator is positive

b) The reaction force applied by the elevator is the same as the weight of the person

Since the force applied and the displacement is in opposite direction, the work done by the elevator is negative

The process in which water vapour and carbon dioxide
traps heat is called the “greenhouse effect”.
The greenhouse effect is a natural phenomenon which
occurs every day. To illustrate an example of this natural phenomenon, d<span>uring the day the Sun shines through the atmosphere.
Earth's surface warms up because of the sunlight. Meanwhile at night in the
absence of the sunlight, Earth's surface cools back and releasing the heat back
into the air. However some of the heat is retained by the greenhouse gases
(such as carbon dioxide and water vapour) in the atmosphere. This process what
keeps our planet Earth warm and cozy at an average temperature of 16°C.</span>
<span>
</span>
<span>Answer:</span>
<span>greenhouse effect</span>
Answer:
h' = 603.08 m
Explanation:
First, we will calculate the initial velocity of the pellet on the surface of Earth by using third equation of motion:
2gh = Vf² - Vi²
where,
g = acceleration due to gravity on the surface of earth = - 9.8 m/s² (negative sign due to upward motion)
h = height of pellet = 100 m
Vf = final velocity of pellet = 0 m/s (since, pellet will momentarily stop at highest point)
Vi = Initial Velocity of Pellet = ?
Therefore,
(2)(-9.8 m/s²)(100 m) = (0 m/s)² - Vi²
Vi = √(1960 m²/s²)
Vi = 44.27 m/s
Now, we use this equation at the surface of moon with same initial velocity:
2g'h' = Vf² - Vi²
where,
g' = acceleration due to gravity on the surface of moon = 1.625 m/s²
h' = maximum height gained by pellet on moon = ?
Therefore,
2(1.625 m/s²)h' = (44.27 m/s)² - (0 m/s)²
h' = (1960 m²/s²)/(3.25 m/s²)
<u>h' = 603.08 m</u>