Question

A boat is travelling at 15 miles per hour. Aman walks across the deck in a direction at a right angle to the direction of the boat at the rate of 6ft. Per seconds. What is the total distance travelled by the man in 1 second with respect to the earth?

Answer 1

velocity of boat (v_b) =15 mile per hour

=22 ft/s

velocity of man(v_m)=6 ft/s

so

displacement of man with respect to boat in 1 sec(s_m) =$v_mt$

$s_m=6\times1=6 ft$

displacement of boat(s_b)=$v_bt$

$s_b=22\times1=22ft$

so displacement of man with respect to earth will be

$s=\sqrt{s_m^2+s_b^2}\\s=\sqrt{6^2+22^2}=22.8 ft$

so displacement of man with respect to earth will be 22.8ft