Question

Renu went to the market between 7 am and 8 am. The angle between the hour-hand and
the minute-hand was 90°. She returned home between 7 am and 8 am. Then also the
angle between the minute-hand and hour-hand 90°. At what time (nearest to second) did
Renu leave and return home?
7 h 18 m 35 s and 7 h 51 m 24 s
7 h 19 m 24 s and 7 h 52 m 14s
7 h 20 m 42 s and 7 h 53 m 11 s
7 h 21 m 49 s and 7 h 54 m 33 s​

Answer 1

Step-by-step explanation:

For the angle to be 90 the gap between the hour & minute hand has to be equivalent to 15 min. As the hour hand is after 7hrs so the minute hand has to be after 20 minutes. The hour hand moves equivalent to 1 minute hand in 12 min. So at 7 : 20 the hour hand will be between 36-37 minutes. So the minute hand will be between 21-22 minutes (36 - 15 = 21). So (D) is the correct answer.

Mark as a brilliant answer......

Answer 2

Answer:

A scalar or scalar quantity in physics is one that can be described by a single element of a number field such as a real number, often accompanied by units of measurement. A scalar is usually said to be a physical quantity that only has magnitude, possibly a sign, and no other characteristics.