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:
0.00970 s
Explanation:
The centripetal force that causes the charge to move in a circular motion = The force exerted on the charge due to magnetic field
Force due to magnetic field = qvB sin θ
q = charge on the particle = 5.4 μC
v = velocity of the charge
B = magnetic field strength = 2.7 T
θ = angle between the velocity of the charge and the magnetic field = 90°, sin 90° = 1
F = qvB
Centripetal force responsible for circular motion = mv²/r = mvw
where w = angular velocity.
The centripetal force that causes the charge to move in a circular motion = The force exerted on the charge due to magnetic field
mvw = qvB
mw = qB
w = (qB/m) = (5.4 × 10⁻⁶ × 2.7)/(4.5 × 10⁻⁸)
w = 3.24 × 10² rad/s
w = 324 rad/s
w = (angular displacement)/time
Time = (angular displacement)/w
Angular displacement = π rads (half of a circle; 2π/2)
Time = (π/324) = 0.00970 s
Hope this Helps!!!
Answer:
Q = 200800 Joules.
Explanation:
Given the following data;
Mass = 4kg
Initial temperature = 30.0°C
Final temperature = 90.0°C
Specific heat capacity of glass = 837 J/kg°C
To find the quantity of heat absorbed;
Heat capacity is given by the formula;
Where;
Q represents the heat capacity or quantity of heat.
m represents the mass of an object.
c represents the specific heat capacity of water.
dt represents the change in temperature.
dt = T2 - T1
dt = 90 - 30
dt = 60°C
Substituting the values into the equation, we have;
Q = 200800 Joules.
Therefore, the amount of heat absorbed is 200800 Joules.
The acceleration of this car is equal to 5 
.
<u>Given the following data:</u>
- Initial velocity = 0 m/s (assuming it's starting from rest).
To determine the acceleration of this car:
<h3>How to calculate acceleration.</h3>
In Science, the acceleration of an object is calculated by subtracting the initial velocity from its final velocity and dividing by the time.
Mathematically, acceleration is given by this formula:
<u>Where:</u>
- U is the initial velocity.
- is the time measured in seconds.
Substituting the given parameters into the formula, we have;
Acceleration, a = 5
Read more on acceleration here: brainly.com/question/24728358
A.) reference group
"A reference group includes individuals or groups that influence our opinions, beliefs, attitudes and behaviors. They often serve as our role models and inspiration"(study.com).
