Question
A plane mirror is placed on a wall. A man walks directly
toward the mirror at 2 m/s. The speed at which his image approaches him is:Solution
In plane mirrors, the image appears the same distance behind the mirror as the object is in front. When the man moves at 2 m/s toward the mirror, the image moves 2 m/s toward him from the opposite side. So, the relative speed between man and image is 2 + 2 = 4 m/s.
14, 20, 29, 44, 65, ?
78, 88, 100, 114, ?, 148
What will come in place of the question mark (?) in the following series?
45, 68, 114, 183, 275, ?
?, 15, 45, 225, 1575, 14175
1236, 1445, 1675, 1933, 2226, ?
152 142 122 ? 52 2
415 246 367 ? 335 310
...What will come in place of the question mark (?) in the following series?
16, 16, ?, 96, 384, 1920
45, ?, 84, 114, 151, 195
7 12 33 ? 635 3804
...