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:
1.45 K
I had the same question and i got it right.
<h2>Acceleration due to gravity in moon is 1.5 m/s²</h2>
Explanation:
We have equation of motion s = ut + 0.5 at²
Here the ball travels 3 m less distance in fifth second compared to third second.
That is
s₃ = s₅ + 3
Now we have
Distance traveled in third second, s₃ = u x 3 - 0.5 x g x 3² - u x 2 - 0.5 x g x 2²
s₃ = u - 2.5 g
Also
Distance traveled in fifth second, s₅ = u x 5 - 0.5 x g x 5² - u x 4 - 0.5 x g x 4²
s₅ = u - 4.5 g
That is
u - 2.5 g = u - 4.5 g + 3
2 g = 3
g = 1.5 m/s²
Acceleration due to gravity in moon = 1.5 m/s²
For purposes of completing our calculations, we're going to assume that
the experiment takes place on or near the surface of the Earth.
The acceleration of gravity on Earth is about 9.8 m/s², directed toward the
center of the planet. That means that the downward speed of a falling object
increases by 9.8 m/s for every second that it falls.
3 seconds after being dropped, a stone is falling at (3 x 9.8) = 29.4 m/s.
That's the vertical component of its velocity. The horizontal component is
the same as it was at the instant of the drop, provided there is no horizontal
force on the stone during its fall.
Here we have to add the two measurements given in the question
The measurement values are given as 1.0090 cm and 0.02 cm.we have to add them on the basis of significant figure rules.
As per the addition rule in terms of significant figures
1-First we have to select the number of significant digits after the decimal point of each quantity.
2-Now we have to remember that during the addition ,the resultant of two quantities will follow the quantity having least number of significant figures after the decimal point.
3-Here we are considering the minimum number of significant figures after the decimal points not the minimum number of significant figures in case of multiplication and division
Now we have to add these two quantities as per the above rule-
1.0090 cm +0.02 cm
=1.0290 cm
Here the result will follow 0.02 which has minimum number of significant figures after the decimal points.
Hence we have to round off the number from 9 of 1.0290
As 9 is greater than 5 ,so he actual result will be 1.03 cm
