Answer:
The tangential speed of the tack is 8.19 m/s.
Explanation:
The wheel rotates 3.37 times a second that means wheel complete 3.37 revolutions in a second. Therefore, the angular speed ω of the wheel is given as follows:

Use the relation of angular speed with tangential speed to find the tangential speed of the tack.
The tangential speed v of the tack is given by following expression
v = ω r
Here, r is the distance to the tack from axis of rotation.
Substitute 21.174 rad/s for ω, and 0.387 m for r in the above equation to solve for v.
v = 21.174 × 0.387
v = 8.19m/s
Thus, The tangential speed of the tack is 8.19 m/s.
Distance = 2AU / tan1.0
If you mean 1.0 is in degrees, then Distance = 114.58 AU
Answer:

Explanation:
Given that
For straight wire
Charge density= λ
For hollow metal cylinder
Charge density=2 λ
We know that electric filed for wire given as


Now the electric filed due to hollow metal cylinder


Now by considering the Gaussian surface r<R then only electric fild due to wire will present.So
At r<R

Answer:
The acceleration is 14.28 km/h^2
Explanation:
Step one:
Given data
initial speed u= 0 km/h
final speed v= 140km/h
time t= 9.8 seconds
Required
The acceleration of the car
Step two:
From a= v-u/t
substitute
a= 140-0/9.8
a=140/9.8
a=14.28 km/h^2