WAEC - Mathematics (2010 - No. 32)
If x km/h = y m/s, then y =
\(\frac{7}{18}\)x
\(\frac{11}{20}\)x
\(\frac{4}{15}\)x
\(\frac{5}{18}\)x
Explicação
x kmh-1 = y ms-1
\(\frac{x km}{1 hr}\) = y ms-1
\(x \times \frac{1km}{1hr}\) = y ms-1
\(x \times \frac{1000m}{60 \times 60s}\) = y ms-1
\(x \times \frac{1000}{3600} \frac{m}{s}\) = y ms-1
\(x \times \frac{5}{18} ms^{-1}\)
\(x \times \frac{5}{18} ms^{-1}\) = y ms-1
y = \(\frac{5}{18}\)x
\(\frac{x km}{1 hr}\) = y ms-1
\(x \times \frac{1km}{1hr}\) = y ms-1
\(x \times \frac{1000m}{60 \times 60s}\) = y ms-1
\(x \times \frac{1000}{3600} \frac{m}{s}\) = y ms-1
\(x \times \frac{5}{18} ms^{-1}\)
\(x \times \frac{5}{18} ms^{-1}\) = y ms-1
y = \(\frac{5}{18}\)x