Answer:
For the given conditions the fundamental frequency is 3728.26 Hertz
Explanation:
We know that for a pipe open at one end and closed at other end the fundamental frequency is given by
where
f is the fundamental frequency
is the speed of sound in air in the surrounding conditions.
L = Length of the pipe
Applying values we get and using speed of sound as 343m/s we get
Answer: 2000 watts
Explanation:
Given that,
power = ?
Weight of object = 200-N
height = 4 m
Time = 4 s
Power is the rate of work done per unit time i.e Power is simply obtained by dividing work by time. Its unit is watts.
i.e Power = work / time
(since work = force x distance, and weight is the force acting on the object due to gravity)
Then, Power = (weight x distance) / time
Power = (200N x 4m) / 4s
Power = 8000Nm / 4s
Power = 2000 watts
Thus, 2000 watts of power is needed to lift the object.
Answer:
They contain iron.
Explanation:
Iron is made of metal and magnets attract to metal Iron.
Answer:
A) Average speed = 18.75 m/s
B) More time is spent at 15 m/s than at 25 m/s.
Explanation:
Let the first distance be d1 and the second distance be d2.
We are given;
d1 = 10 km = 10000 m
d2 = 10 km = 10000 m
Speed; v1 = 15 m/s
Speed; v2 = 25 m/s
Now, the formula for distance is; Distance = speed x time
Thus:
d1 = v1 x t1
t1 = d1/v1 = 10000/15 = 666.67 seconds
Also,
d2 = v2 x t2
t2 = d2/v2 = 10000/25 = 400 seconds
Average speed = total distance/total time = (10000 + 10000)/(666.67 + 400) = 18.75 m/s
From earlier, since t1 = 666.67 seconds and t2 = 400 seconds, then;
More time at 15 m/s than at 25 m/s.
Given that metal cases of electrical appliances are connected to the wire, let's select the statement which is not correct from the list of statements.
The earth wire is used to protect you and help reduce the risk of receiving an electric shock. The earth wire reduces the risk of electric shock by creating a path for a fault or lose current to flow to the Earth.
The Live wire may become loose and touch the metal case. In this case, the earth wire will channel the fault current to the earth thereby reducing the risk of electric shock.
If the metal case becomes live, the earth wire conducts current to the ground. This helps prevent electric shock from the metal case.
The Earth wire has low or no resistance. It is always made of copper.
It provides a low resistance path to the ground.
Therefore, the statement ''the earth wire needs to have high resistance'' is NOT current.
ANSWER:
C. The earth wire needs to have a high reistance.
