Question

a container 50 meters long passes a platform 100 meters long in 10 seconds. The speed of the container in km/hr is

options : 36, 48, 54, 25​

Answer 1

Option 3 : 54km/hr

Given :

• a container 50 meters long passes a platform 100 meters long in 10 seconds

To find :

• The speed of the container in km/hr

Solution :

$\sf{distance \: travel \: by \: container \: to \: cross \: platorm} \\ \\ \implies \sf{length \: of \: container + length \: of \: platform} \\ \\ \implies\sf{ 50 + 100} \\ \\\implies \sf{150 \: m/sec} \\ \\ \sf{speed = \dfrac{150}{10}} \\ \\ \implies\sf{15} \\ \\ \implies \sf{15 \times \frac{18}{5} \: km/hr} \\ \\ \implies\sf{3 \times 18 \: km/hr} \\ \\ \implies\large{\boxed{\red{\sf{54 \: km/hr}}}}$

∴ The speed of container is 54 km/hr

Some other Formulas :

• Speed = d/t

• F = m. a

• a (bar) = v - v_0/t = Δv/Δt

• w = F x d

• P = W/Δt

• V = 1R

• PE = mgh

• p = mv

Answer 2

Answer:

• If there is any Vertical Length or Distance, then we Add all Lengths to become Distance.

⠀

$\underline{\bigstar\:\textsf{According to the given Question :}}$

$:\implies\sf Distance=Speed \times Time\\\\\\:\implies\sf (50 + 100) \:m = Speed \times 10 \:s\\\\\\:\implies\sf 150 \:m = Speed \times 10 \:s\\\\\\:\implies\sf \dfrac{150 \:m}{10 \:s} = Speed\\\\\\:\implies\sf Speed = 15 \:m/s\\\\\\:\implies\sf Speed = 15 \times \dfrac{18}{5}\:km/hr\\\\\\:\implies\sf Speed = 3 \times 18\:km/hr\\\\\\:\implies\underline{\boxed{\sf Speed = 54\:km/hr}}$

⠀

$\therefore\:\underline{\textsf{Speed of the container is C) \textbf{54 km/hr}}}.$