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:
C) The ratio of the change in an object's length to its original length when stretched or compressed.
Explanation:
The formula for strain is:
Strain = Change in Length/Origin Length
Hence, it can be described as the percentile of change in the dimension with respect to the original dimension. So, whenever a tensile or a compressive force is applied on a body, its length changes. The ratio of this change to original length is called strain. So, the correct option is:
C) <u>The ratio of the change in an object's length to its original length when stretched or compressed.</u>
1.
<span>The Galápagos Islands contain more different species than any comparable place on the earth.
2.</span>
<span>Their aim is to prevent extinctions.
3.</span>
<span>a gas that absorbs and re-releases heat radiated by the earth
4</span>
<span>acid rain
5.</span>
<span>stratospheric ozone
6</span>
<span>methane
7.</span>
landfill
8.
<span>catalytic converter</span>
Answer:
Zero
Explanation:
Two long parallel wires each carry the same current I in the same direction. The magnetic field in wire 1 is given by :
Magnetic force acting in wire 2 due to 1 is given by :
Similarly, force acting in wire 1 is given by :
According to third law of motion, the force acting in wire 1 will be in opposite direction to wire 2 as :
So, the total magnetic field at the point P midway between the wires is in what direction will be zero as the the direction of forces are in opposite direction.
