Answer:
v = 23
Explanation:
Formatting the question gives;
a = mg - kv² / m
Make v subject of the formula as follows;
(i) Multiply both sides by m
ma = m²g - kv²
(ii) Collect like terms
kv² = m²g - ma
(iii) Divide through by k
v² = (m²g - ma) / k
(iv) Take the square root of both sides
v = √ [(m²g - ma) / k] --------------(ii)
From the question:
a = 2.8
m = 12
g = 9.8
k = 8/3
Substitute these values into equation (i) as follows;
v = √ [(12²(9.8) - 12(2.8)) / (8/3)]
v = √ [(1411.2 - 33.6) / (8/3)]
v = √ [1377.6 / (8/3)]
v = √ [1377.6 x (3/8)]
v = √ [1377.6 x 3 / 8)]
v = √ [516.6]
v = 22.73
v = 23 [to the nearest whole number]
Therefore v = 23 to the nearest whole number