Answer:
t = 1,144 s
Explanation:
The simple pendulum consists of an inextensible string with a mass at the tip, the angular velocity of this is
w = √( L / g)
The angular velocity is related to the frequency and period
w = 2π f
f = 1 / T
w = 2π / T
Let's replace
2π / T = √ (L / g)
T = 2π √ (g / L)
Let's calculate
T = 2π √ (9.81 / 18.5)
T = 4,576 s
The definition of period in the time it takes the ball to come and go to a given point (a revolution) in our case we go from the end to the middle point that is a quarter of the path
t = T / 4
t = 4,576 / 4
t = 1,144 s
In order to tell a river lock attendant that you wish to go through the lock, you should <span>sound one prolonged blast followed by one short blast.
You should wait about 400 feet away from the lock and wait for the flashing light signal that allows you to enter.
Also note that </span><span>commercial traffic always have the first priority in entering the locks.</span>
Answer:
V=15.3 m/s
Explanation:
To solve this problem, we have to use the energy conservation theorem:

the elastic potencial energy is given by:

The work is defined as:

this work is negative because is opposite to the movement.
The gravitational potencial energy at 2.5 m aboves is given by:

the gravitational potential energy at the ground and the kinetic energy at the begining are 0.

Answer:
857.5 m
2.8583×10⁻⁶ seconds
Explanation:
Time taken by the sound of the thunder to reach the student = 2.5 s
Speed of sound in air is 343 m/s
Speed of light is 3×10⁸ m/s
Distance travelled by the sound = Time taken by the sound × Speed of sound in air
⇒Distance travelled by the sound = 2.5×343 = 857.5 m
⇒Distance travelled by the sound = 857.5 m
Time taken by light = Distance the light travelled / Speed of light

Time taken by light = 2.8583×10⁻⁶ seconds