Answer:
a. 3 s.
Explanation:
Given;
angular acceleration of the wheel, α = 4 rad/s²
time of wheel rotation, t = 4 s
angle of rotation, θ = 80 radians
Apply the kinematic equation below,

Given initial angular velocity, ω₀ = 0
Apply the kinematic equation below;

Therefore, the wheel had been in motion for 3 seconds.
a. 3 s.
15.0 I’m pretty sure that’s the answer to your question
Answer:
129.6 seconds
Explanation:
Given that :
α = 0.0002°c-1
θ1 = 20°C
θ2 = 5°C
Time t = one day ; Converting to seconds ; number of seconds in a day ; (24 * 60 * 60) = 86400 seconds
Let dT= change in time
Using the relation :
dT = 0.5* α * dθ * t
dθ = (20 - 5) = 15°C
dT = 0.5 * 0.0002 * 15 * 86400
dT = 129.6 seconds
Answer:
False
Explanation:
The torque exerted by a force is given by:

where
F is the magnitude of the force
d is the distance between the point of application of the force and the pivot
is the angle between the directions of F and d
We see that the magnitude of the torque depends on 3 factors. In this problem, we have 2 forces of equal magnitude (so, equal F). Moreover, one of the forces (let's call it force 1) acts farther from the pivot than force 2, so we have

However, this does not mean that force 1 produces a greater torque. In fact, it also depends on the angle at which the force is applied. For instance, if the first force is applied parallel to d, then we have

and the torque produced by this force would be zero.
So, the statement is false.
Answer:
An insulator holds charge within its atomic structure. Objects with like charges repel each other, while those with unlike charges attract each other. A conducting object is said to be grounded if it is connected to the Earth through a conductor.
Explanation:
Source:https://courses.lumenlearning.com/physics/chapter/18-2-conductors-and-insulators/