Answer:
a. 0.21 rad/s2
b. 2.205 N
Explanation:
We convert from rpm to rad/s knowing that each revolution has 2π radians and each minute is 60 seconds
200 rpm = 200 * 2π / 60 = 21 rad/s
180 rpm = 180 * 2π / 60 = 18.85 rad/s
r = d/2 = 30cm / 2 = 15 cm = 0.15 m
a)So if the angular speed decreases steadily (at a constant rate) from 21 rad/s to 18.85 rad/s within 10s then the angular acceleration is
b) Assume the grind stone is a solid disk, its moment of inertia is
Where m = 28 kg is the disk mass and R = 0.15 m is the radius of the disk.
So the friction torque is
The friction force is
Since the friction coefficient is 0.2, we can calculate the normal force that is used to press the knife against the stone
Answer:hmm not sure on that one
Explanation:
No,because they may have more particles
The ones with pH greater than 7
Explanation:
A pH scale is a scale for expressing the level of acidity or alkalinity of aqueous solutions.
This scale is called a pH or pOH scale. The pH is the common one.
pH of a solution is the negative logarithm to base 10 o the hydrogen ion concentration of the solution.
- The scale ranges from 1 through 14.
- An acidic solution has a pH value less than 7. Neutral solutions have pH of 7 and basic solutions have pH greater than 7.
learn more:
acidity brainly.com/question/5121777
#learnwithBrainly
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