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:
The mass of the wheel is 2159.045 kg
Explanation:
Given:
Radius 
m
Force
N
Angular acceleration 
From the formula of torque,
Γ
(1)
Γ
(2)

Find momentum of inertia
from above equation,



Find the momentum inertia of disk,



Kg
Therefore, the mass of the wheel is 2159.045 kg
Acceleration of cheetah (a) = 4m/s²
time = 10s
initial velocity(u) = 0
final velocity = v
distance travelled = s
v = u +at = 0 + 10×4 = 40m/s
s = (v²-u²)/2a = 40²/(2×4) = 1600/8 = 200m
Niobium wire with a 2.60 mm diameter has a maximum current capacity of 500 A while still remaining superconducting.
<h3>Describe the present.</h3>
Current is the rate at which charge passes from one point on a circuit to another. In a circuit, a significant current flows when several coulombs or charge pass over the cross section of a wire. When the charge carriers are firmly packed inside the wire, high currents can be generated at low speeds.
<h3>What do current and electron actually mean?</h3>
Electron movement is referred to as electron current. The positive terminal receives electrons that are released by the negative terminal. Traditional current, usually referred to as just current, exhibits behavior consistent with positive charge carriers being the source of current flow. Regular current is received at the positive end and then flows to a negative terminal.
To know more about current visit:
brainly.com/question/15141911
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Thank you for posting your question here at brainly. But your question seems incomplete. I will assume you based the situation below:
<span>An electrons moves at 2.0x10^6 m/s through a region in which there is a magnetic field of unspecified direction and magnitude 7.4x10^-2 T.
The </span> largest possible magnitude of the acceleration of the electron due to the magnetic field is <span>= 2.6 × 10 ¹⁶ m / s ²</span>