Lesson Example Discussion Quiz: Class Homework |
Step-3 |
Title: Miscellaneous - 2 |
Grade: 7-a Lesson: S1-L10 |
Explanation: |
| Step | Type | Explanation | Answer |
|---|---|---|---|
1 |
Problem |
How long will john take to make a round of a circular field of radius 21m cycling at the speed of 8km/hr? |
|
2 |
Given |
The radius of the circular field is 21 m and John is cycling at the speed of 8 km/hr. |
|
3 |
Formula: |
Circumference of the circular field |
\$C = 2 \pi r\$ |
4 |
Step |
Substitute \$22/7\$ for \$\pi\$ and 21 for r. |
\$C = 2 \times \frac{22}{7} \times 21\$ |
5 |
Step |
Cancel out common factor |
\$C = 2 \times \frac{22}{\cancel{7}^1} \times \cancel{21}^3\$ |
6 |
Step |
Multiply |
\$C = 132 \$ |
7 |
Step |
John is cycling at the speed 8 km/hr |
|
8 |
Step |
In 1 hour John covers 8 km. |
8 km = 8000 m |
9 |
Step |
So, time required to cover 132 m is |
\$\frac{132}{8000} = 0.0165 \$ hours |
10 |
Step |
By converting 0.0615 hours into minutes, we get |
\$0.0615 = 0.0615 \times 3600\$ |
11 |
Answer |
John take to 59.4 seconds a round of a circular field of radius 21m cycling at the speed of 8km/hr |
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