With constant angular acceleration
, the disk achieves an angular velocity
at time
according to

and angular displacement
according to

a. So after 1.00 s, having rotated 21.0 rad, it must have undergone an acceleration of

b. Under constant acceleration, the average angular velocity is equivalent to

where
and
are the final and initial angular velocities, respectively. Then

c. After 1.00 s, the disk has instantaneous angular velocity

d. During the next 1.00 s, the disk will start moving with the angular velocity
equal to the one found in part (c). Ignoring the 21.0 rad it had rotated in the first 1.00 s interval, the disk will rotate by angle
according to

which would be equal to

Answer:
0.075 T
Explanation:
When a current-carrying wire is immersed in a region with magnetic field, the wire experiences a force, given by

where
I is the current in the wire
L is the length of the wire
B is the strength of the magnetic field
is the angle between the direction of I and B
In this problem we have:
L = 0.65 m is the length of the wire
I = 8.2 A is the current in the wire
F = 0.40 N is the force experienced by the wire
since the current is at right angle with the magnetic field
Solving the formula for B, we find the strength of the magnetic field:

Answer:
(a) 104 N
(b) 52 N
Explanation:
Given Data
Angle of inclination of the ramp: 20°
F makes an angle of 30° with the ramp
The component of F parallel to the ramp is Fx = 90 N.
The component of F perpendicular to the ramp is Fy.
(a)
Let the +x-direction be up the incline and the +y-direction by the perpendicular to the surface of the incline.
Resolve F into its x-component from Pythagorean theorem:
Fx=Fcos30°
Solve for F:
F= Fx/cos30°
Substitute for Fx from given data:
Fx=90 N/cos30°
=104 N
(b) Resolve r into its y-component from Pythagorean theorem:
Fy = Fsin 30°
Substitute for F from part (a):
Fy = (104 N) (sin 30°)
= 52 N