Answer:
Yes the ramp can be safely used
Explanation:
Here, we have
Length of longest ramp = 5 ft
Height of wall = 2 ft
Therefore, the sine of the angle adjacent to the ramp which is equal to the angle of elevation is given by;

Where:
The opposite side to angle = 2 ft wall and
Hypotenuse side = Ramp = 5 ft
Therefore,
and θ = sin⁻¹0.4 = 23.55 °
The ramp can be safely used as the angle it is adjacent to is less than the specified 30°.
Force is a push or a pull upon an object, resulting the objects interaction with another object
Answer: LET'S TAKE GRAVITY ON EARTH AS 10 N/KG AND ON MOON AS 0.6 N/KG
a) weight=15kgx10N/kg
= 150N
b) weight=15x0.6=9N
c) mass=is the same so 15kg
d) mass is measured in kg, weight in NEWTONS OR 
e) when the gravitational force is zero
Explanation: