Question

If a=mg-kv2/m,find,correct to the nearest whole number the value of v when a=2.8,m=12,g=9.8 and k=8/3

Answer 1

Answer:

v = 23

Step-by-step 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