<span>Frequency = 394 Hz
Length of the string L = 81 cm = 0.81 m
Mass of the string = 0.002 kg
Tension T = ?
Wave length of the string is two times the length.
n x lambda = 2L, we also have lambda = vt = v / f, t is time period and given n = 1.
Therefore L = v / 2f => v = 2fL
Deriving form force equation, force here is tension T so
v = squareroot of (TL/m) hence
2fL = squareroot of (TL/m) => 4 x f^2 x L^2 = (T x L) / m => T = 4 x f^2 x L x m
T = 4 x 0.81 x (394)^2 x 0.002 = 4 x 0.81 x 155236 x 0.002
T = 1005.9 N = 1.006 x 10^3 N</span>
Answer:
speed = 44.9m/s
x = 35.5 m, y = 58.0m
Explanation:
A car on a circular track with constant angular velocity ω can be described by the equation of position r:

The velocity v is given by:

The acceleration a:

From the given values we get two equations:

We also know:

The magnitude of the acceleration a is:

The magnitude of position r is:

Plugging in to the equation for a(t):

and solving for ω:

Now solve for time t:

Using the calculated values to compute v(t):

The speed of the car is:

The position r:

Answer:
There will be no change in the direction of the electric field .
Explanation:
The direction will remain the same because the sign of the charges has no effect on it.
When one replaces the conducting cube with one that has positive charge carriers there will be no change in the direction of the field as there is no defined relationship between the direction of the electric field and sign of the charge.
First, torque is equal to force times the distance. for the first force that is applied, the torque is zero because is applied at the hinge. so the net torque:
t = ( 12 N ) ( 0 m ) ( cos 30 ) + ( 12 N ) ( 1.68 m ) cos 45
t = 14.26 Nm is the torque with respect to the hinge