Math Problem Statement

The wheel of a lorry has radius 182 cm What are the no of revolutions lorry will make in a minute if its speed is 66Km/hr?

Solution

To solve this problem, we'll need to follow these steps:

Step 1: Convert the speed of the lorry from km/hr to cm/min

Given:

  • Speed of the lorry = 66 km/hr

First, convert the speed to cm/min:

  • 1km=1000m=100000cm1 \, \text{km} = 1000 \, \text{m} = 100000 \, \text{cm}
  • 1hr=60min1 \, \text{hr} = 60 \, \text{min}

So, the speed in cm/min is: 66km/hr=66×100000cm/hr=6600000cm/hr66 \, \text{km/hr} = 66 \times 100000 \, \text{cm/hr} = 6600000 \, \text{cm/hr} 6600000cm/hr÷60min/hr=110000cm/min6600000 \, \text{cm/hr} \div 60 \, \text{min/hr} = 110000 \, \text{cm/min}

Step 2: Calculate the circumference of the wheel

The circumference CC of the wheel is given by the formula: C=2πrC = 2\pi r where rr is the radius of the wheel.

Given:

  • Radius of the wheel r=182cmr = 182 \, \text{cm}

So, the circumference is: C=2×π×182cm=364πcmC = 2 \times \pi \times 182 \, \text{cm} = 364\pi \, \text{cm}

Step 3: Calculate the number of revolutions per minute

The number of revolutions NN made by the wheel in one minute can be found by dividing the distance traveled in one minute by the circumference of the wheel: N=Distance traveled in one minuteCircumference of the wheelN = \frac{\text{Distance traveled in one minute}}{\text{Circumference of the wheel}} N=110000cm364πcm1100001143.8696.15N = \frac{110000 \, \text{cm}}{364\pi \, \text{cm}} \approx \frac{110000}{1143.86} \approx 96.15

Final Answer:

The lorry will make approximately 96 revolutions per minute.

Would you like a more detailed explanation or have any other questions?


Here are 8 related questions to expand your understanding:

  1. How would the number of revolutions change if the lorry's speed increased to 80 km/hr?
  2. What would be the number of revolutions if the radius of the wheel were halved?
  3. How does the number of revolutions change if the lorry's speed is reduced to 33 km/hr?
  4. What is the relation between the radius of the wheel and the number of revolutions?
  5. If the wheel's circumference were doubled, how would that affect the number of revolutions?
  6. What is the distance covered by the lorry in 10 minutes?
  7. How would the result change if the radius of the wheel was given in meters instead of centimeters?
  8. What is the time required for the lorry to travel 1 km at the given speed?

Tip: When working with circular motion problems, always ensure units are consistent, especially when dealing with speed and distances.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Geometry
Trigonometry
Circular Motion

Formulas

Circumference of a circle: C = 2πr
Revolutions per minute: N = Distance / Circumference

Theorems

-

Suitable Grade Level

Grades 9-12