Abody covers one revolution around a circular park of circumference 176m in 4 minutes. find the displacement of the body after 6 minutes

Total distance around the track is 176m.

Speed of the body = total distance covered/total time taken

                                 = 176/4

                                 =44metres/min

Find the distance covered in 6 minutes:

                           if 1 min= 44m

                           then 6 min=(44X6)/1 =264

There the distance covered around the track from starting point = 264-176

                                                                                                             =88 metres

This corresponds to distance around half the track, which means displacement corresponds to 180 degrees

Hence, the displacement distance is the diameter.

total distance around the track= 176m

Circumference=Xdiameter176=22/7 XD

                                                                       D=176X7/22

                                                                     =56 (therefore the displacement is                                                                                            56meters)

Boat speed = 8 miles/hr

Explanation:

Let the speed of the boat be U

Let the speed of the current be V.

Therefore, the downstream speed is U+V

and the upstream speed is U-V

Now we know that Speed = distance / time

Therefore, downstream speed, U+V = 63 / 7

                                                    U+V = 9 miles/hr   (1)

                  Upstream speed, U-V = 63 / 9

                                                U-V = 7 miles/hr      (2)

Therefore subtracting (2) from (1), we get

( U+V) - ( U-V ) = 9-7

2V = 2

V = 1 miles/hr

Therefore the speed of the current is V = 1 mile/hr

Now from (1) we get

U+V = 9

U+1 = 9

U = 8

Therefore, the speed of the boat is U = 8 miles/hr