Answer:
a. 
b. 
Explanation:
I have attached an illustration of a solid disk with the respective forces applied, as stated in this question.
Forces applied to the solid disk include:

Other parameters given include:
Mass of solid disk, 
and radius of solid disk, 
a.) The formula for determining torque (
), is 
Hence the net torque produced by the two forces is given as a summation of both forces:

b.) The angular acceleration of the disk can be found thus:
using the formula for the Moment of Inertia of a solid disk;

where
= Mass of solid disk
and
= radius of solid disk
We then relate the torque and angular acceleration (
) with the formula:

Acceleration = velocity/time
A= 3.5m/s/15s
A= 0.23m/s^2
Answer:
a =3.33 m/s²
Explanation:
given,
initial speed of Plane, u = 0 m/s
final speed of plane, v = 60 m/s
time of the acceleration, t = 18 s
average acceleration of the plane, a = ?
average acceleration is equal to change in velocity per unit time.



a =3.33 m/s²
Hence, average acceleration of the plane is equal to a =3.33 m/s²
E. all of the above
An umbrella tends to move upward on a windy day because _<span>A. buoyancy increases with increasing wind speed </span>
<span>B. air gets trapped under the umbrella and pushes it up </span>
<span>C. the wind pushes it up </span>
<span>D. a low-pressure area is created on top of the umbrella </span>