Question

Find the speed of two objects if, when they move uniformly towards each other they get 4 m closer in every sec and when they move uniformly in the same direction with their original speeds, they get 4m closer every 10s.

• A. 1.8 m/s, 1.6 m/s
• B. 2 m/s, 1.8 m/s
• C. 2.2 m/s, 1.8 m/s
• D. 1.6 m/s, 1.4 m/s

Answer 1

The correct option is C 2.2 m/s, 1.8 m/s

Let v and V be their velocities.

According to question

$v+V=4m/s$

And, $v-V=\frac{4}{10}=0.4m/s$

Adding Both equation

$(v+V)+(v-V)=4+0.4$

$\Rightarrow 2v=4.4m/s$

$\Rightarrow v=2.2m/s$

On subtracting

$(v+V)-(v-V)=4-0.4$

$\Rightarrow 2V=3.6m/s$

$\Rightarrow V=1.8m/s$

Therefore, C is correct option.