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An ordinary workshop grindstone has a radius of 7.50 cm and rotates at 6500 rev/min. What is the linear speed of a point on its edge?

a) 20.3 m/s
b) 23.6 m/s
c) 26.9 m/s
d) 30.2 m/s

User Telkins
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1 Answer

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Final answer:

The linear speed of a point on the edge of a 7.50 cm radius workshop grindstone rotating at 6500 rev/min is approximately 51.13 m/s. This speed is calculated using the formula v = r * ω and converting the rotational speed from rev/min to rad/s.

Step-by-step explanation:

Calculating the Linear Speed of a Point on the Grindstone's Edge

The question involves finding the linear (or tangential) speed of a point on the edge of a workshop grindstone that has a radius and rotates at a known speed. First, we'll convert the rotational speed from revolutions per minute (rev/min) to radians per second (rad/s), and then use this to find the linear speed.

Given:

  • Radius (r): 7.50 cm (or 0.075 m)
  • Rotational speed: 6500 rev/min

Using the formula for linear speed v = r * ω, where ω is the angular speed, we can calculate v as follows:

  • Convert rev/min to rad/s: ω = 6500 rev/min * (2π rad/rev) * (1 min/60 s)
  • ω ≈ 681.77 rad/s
  • Linear speed v = 0.075 m * 681.77 rad/s
  • v ≈ 51.13 m/s

Therefore, the linear speed of a point on the edge of the grindstone is approximately 51.13 m/s.

User Yan Yang
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