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

Since initial velocity is zero hence , u = 0
=> d = 1/2 * a * t2

on solving we get
d = 86.436 metres
Note ; Here Gravitational Acceleration is take as , g = 9.8 m/s2
Answer:
Weight = 966 Newton.
Explanation:
Given the following data;
Length = 1.2 m
Width = 2.3 m
Pressure = 350 Pa
To find the weight of the tank;
We know that weight is the force of gravity acting on an object multiplied by its mass.
Weight = mg = force
Hence, we would determine the force using the parameters that were given.
But we would first determine the area of the rectangular tank.
Area of rectangle, A = length * width
A = 1.2 * 2.3
A = 2.76 m²
Mathematically, pressure is given by the formula;
Pressure = force/area
Force = pressure * area
Substituting into the formula, we have;
Force = 2.76 * 350
Force = 966 Newton
Therefore, the weight of the tank is 966 Newton.
C) because you could get hurt if certain items fall in it and you are in water
The atom in an excited state has more energy and is less stable than the atom in the ground state.