A man moves on a straight road from point A to point C. She takes 20 minutes to cover a certain distance AB and 30 minutes to cover the rest of distance BC. Man then turns back and takes 30 minutes to cover the distance CB and 20 minutes to cover the rest of the distance to his starting point. Man makes 10 rounds on the road the same way. The motion of the man is
(a) only rectilinear motion.
(b) only periodic motion.
(c) rectilinear and periodic both.
(d) neither rectilinear nor periodic
Answers
Answer:
option c is the correct ans
Explaination:
as the path is straight the motion is rectilinear
as the path is straight the motion is rectilinearand as the behaviour in motion is repetitive it is also periodic
as the path is straight the motion is rectilinearand as the behaviour in motion is repetitive it is also periodictherefore option c .
Answer:
Option 3☑️☑️
◆ Answer -
(d) |AB| = 8.5 m
● Explaination -
Let i, j & k be unit vectors along X-axis, Y-axis & Z-axis.
A = i + 2j - 3k
B = 3i + 4j + 5k
Displacement of the man is calculated by -
AB = B - A
AB = (3i + 4j + 5k) - ( i + 2j - 3k)
AB = 2i + 2j + 8k
Magnitude of displacement is calculated by -
|AB| = √(2² + 2² + 8²)
|AB| = √(4 + 4 + 64)
|AB| = √(72)
|AB| = 2√18
|AB| = 8.48 m
From the options, 8.5 m is the most appropriate.