Answer:
Speed will be: 1.33ft/s
Explanation:
If ladder is 10 ft long and bottom is 8 ft from the wall then by Pythagoras theorem we can find the height of the wall where ladder touches. (before it started slipping)
thus 
Giving x= 6 ft. If the ladder is falling with a speed of 4ft/s it will take 1.5 seconds to cover the 6ft distance.
This shows that the bottom of ladder will travel from 8ft to 10 ft in 1.5 seconds. Thus covering 2 ft in 1.5 seconds making the speed to be:
v = S / t
v = 2 / 1.5
v = 1.33 ft/s
Answer:
80%
Explanation:
Thermal efficiency is a measure of the extent to which a heat engine is able to convert to other form. It is measure in percentage.
Thermal efficiency = 
× 100%
Where 
is the input energy and 
is the output energy.
Given that: = 2400 J and = 3000 J, therefore:
Thermal efficiency = 
× 100%
= 80%
The thermal efficiency of the engine is 80%.
To find the pressure with a given data for the height, you are asked to get the hydraulic pressure. Hydraulic pressure has the following formula:
P = density*acceleration due to gravity*height
Assume that the density of seawater is the same as that for pure water,density = 1000 kg/m^3.
P = 1000 kg/m3*9.81m/s2*9100m
P = 89271000 Pascals or 89.271 megapascals
