Answer:
(a) 0 kJ
(b) 9.81 kJ
(c) 31.32 m/s
Explanation:
(a)
From the law of conservation of energy, energy can only be transformed from one state to another. At a height of 50 m, all the kinetic energy is converted to potential energy hence KE=0
(b)
Potential energy, PE=mgh where m is the mass, g is acceleration due to gravity and h is the height
Substituting 50 m for h and 20 Kg for m, taking g as 9.81 then
PE=20*9.81*50=9810 J=9.81 kJ
(c)
Relating the equation of potential energy to the equation of kinetic energy, which is 
where v is the velocity of the mass
Substituting 50 m for h and taking g as 9.81 then
Question Continuation
True or False?
Answer:
False
Explanation:
Given
Columns: book_title and year_released
SQL statement: SELECT book_title, year_released FROM books GROUP BY year_released
Expected Result: To select the number of books released each year
Although the GROUP BY used in the SQL statement is meant to group rows with same values into summary rows but it's not user properly because the GROUP BY clause, as used here needs the COUNT aggregate functions to group the result-set by one or more columns.
Answer:
causes: unemployment, poverty,Lack of education,urbanization e.t.c
solutions:making people educated, giving people jobs
Answer: True
Explanation:
The east-west row planting orientation helps in the maximize the light absorption by plants which then brings about an efficient photosynthesis activity.
Also, it helps in the shading of weeds that can be found in the inter-row space. Also, it brings about an improvement on drop yield crop yield.
Therefore, the answer to the above is true.
Answer:
the evaluation in SI unit will be 
Explanation:
We have evaluate 
We know that 1 mm 
So 240 mm 
Newton can be written as 
So 
So the evaluation in SI unit will be
