3. A body travels 200 cm in the first 2 s and 220 cm in the next 5 s. Calculate the velocity at the end of the seventh second from the start.



Answer :

To determine the velocity of the body at the end of the seventh second from the start, we need to follow a systematic approach. Here is a detailed step-by-step solution:

1. Identify the total distance traveled:
- The body travels 200 cm during the first 2 seconds.
- The body then travels 220 cm during the next 5 seconds.

Thus, the total distance traveled by the body is:

[tex]\[ \text{Total Distance} = 200 \, \text{cm} + 220 \, \text{cm} = 420 \, \text{cm} \][/tex]

2. Calculate the total time taken:
- The time taken for the first section of the journey is 2 seconds.
- The time taken for the next section of the journey is 5 seconds.

Therefore, the total time taken by the body is:

[tex]\[ \text{Total Time} = 2 \, \text{s} + 5 \, \text{s} = 7 \, \text{s} \][/tex]

3. Determine the average velocity:
- Velocity is defined as the total displacement divided by the total time taken.

Thus, the velocity is:

[tex]\[ \text{Velocity} = \frac{\text{Total Distance}}{\text{Total Time}} = \frac{420 \, \text{cm}}{7 \, \text{s}} = 60 \, \text{cm/s} \][/tex]

So, the velocity of the body at the end of the seventh second from the start is [tex]\(60 \, \text{cm/s}\)[/tex].

Therefore, the final result is:
[tex]\[ \text{Velocity at the end of the seventh second} = 60 \, \text{cm/s} \][/tex]