Answer:
Newtons first law
Explanation:
Objects stay at rest until a force acts on it causing it to move from its resting position
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

Limestone, Sandstone, and Shale would be the answer.
We know for a fact that D and A can be eliminated from the answer choices because those are both false. we know that both B and C are both very accurate knowing that wave B does have a higher pitch than wave A but also wave A has a louder sound wave than wave B. so i'd say the answer is (C).
Answer:

Explanation:
Acceleration is the change in velocity over time.

The object accelerates <em>from</em> 45 meters per second <em>to </em>10 meters per second in 5 seconds. Therefore,

Substitute the values into the formula.

Solve the numerator.

Divide.


The acceleration of the object is -7 meters per square second. The acceleration is negative because the object's velocity decreases and the object slows down.