Answer:
27.95[kW*min]
Explanation:
We must remember that the power can be determined by the product of the current by the voltage.
where:
P = power [W]
V = voltage [volt]
I = amperage [Amp]
Now replacing:
Now the energy consumed can be obtained mediate the multiplication of the power by the amount of time in operation, we must obtain an amount in Kw per hour [kW-min]
Explanation:
Power of electric kettle, P = 1 kW
Voltage, V = 220 V
(a) Electric power is given by the formula as follows :
R is resistance
(b) When connected to a 220 V supply, it takes 3 minutes for the water in the kettle to reach boiling point.
Energy supplied is given by :
P is power,
Answer:
It's 1.0000042 times longer in summer than in winter. It represents a 1.6 centimeters difference between seasons.
Explanation:
The linear coefficient of thermal expansion for steel is about . From the equation of linear thermal expansion, we have:
Taking the winter day as the initial, and the summer day as the final, we can take the relationship between them:
It means that the bridge is 1.0000042 times longer in summer than in winter. If we multiply it by the length of the bridge, we obtain that the difference is of about 1.6 centimeters between the two seasons.
Answer:
32.3 m/s
Explanation:
The ball follows a projectile motion, where:
- The horizontal motion is a uniform motion at costant speed
- The vertical motion is a free fall motion (constant acceleration)
We start by analyzing the horizontal motion. The ball travels horizontally at constant speed of
and it covers a distance of
d = 165 m
So, the total time of flight of the ball is
In order to find the vertical velocity of the ball, we have now to analyze its vertical motion.
The vertical motion is a free-fall motion, so the ball is falling at constant acceleration; therefore we can use the following suvat equation:
where
is the vertical velocity at time t
is the initial vertical velocity
is the acceleration of gravity (taking downward as positive direction)
Substituting t = 3.3 s (the time of flight), we find the final vertical velocity of the ball:
Answer:
Explanation:
In an ideal transformer, the ratio of the voltages is proportional to the ratio of the number of turns of the windings. In this way:
In this case:
Therefore, using the previous equation and the data provided, let's solve for :
Hence, the number of loops in the secondary is approximately 41667.