Answer:
2.4s
Explanation:
The length of the pendulum = 75ft
Diameter d = 12 inches
The time period of the pendulum is given as
T = 2pi(L/g)^1/2
Then the time it takes to move from displacement to equilibrium is given as:
t = T/4
= (Pi/2)*(L/g)^1/2
= pi/2 x [(75x0.3048)/9.81]^0.5
= 1.57x[22.86/9.81)^0.5
= 2.4s
2.4 seconds is the least amount of time that it would take.
The wire vibrates back and forth between the poles of the magnet.
The frequency of the vibration is the frequency of the AC supply.
Balance would be the answer to this questions
The gravitational potential energy of an object depends on three things. Its mass, its height above the surface of the earth and the pull of gravity (which is assumed to always be 9.8 m/s².
The Formula for finding the GPE is : m x g x h where m = mass, g = gravitational acceleration and h is height from earth's surface.
Using this formula we can find that :
GPE= 75 x 9.8 x 300 = 220500J (where J is the SI unit for GPE and stands for Joules.
Going upstream against the current gives a net speed equivalent to the speed at still water minus the speed of the current. Consequently, the speed downstream gives a net speed equal to the speed at still water plus the speed of the current, making it travel faster. The solution is:
UPSTREAM
v = 20 - 1.5 = 18.5 km/h
t = 30 mins or 0.5 hours
distance = 18.5km/h (0.5 h) = 9.25 km
DOWNSTREAM
for the same distance of 9.25 km:
v = 20 + 1.5 = 21.5 km/h
t = 9.25km / 21.5 km/h = 0.43 hours or 25.8 mins = 26 mins --> FINAL ANS.
