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.
Answer:
Angle of reflection of light is 34 degree
Explanation:
As per law of reflection of light we know that
angle of incidence of light = angle of reflection of light
So here we know that
angle of incidence on the surface of oil is given as

so we know that

so here we can say that reflection angle of light will be same as angle of incidence

Answer:
A. 20 N
Explanation:
the weight of book is 2×10= 20N
Answer: 500 Watts
Explanation:
Power
is the speed with which work
is done. Its unit is Watts (
), being
.
Power is mathematically expressed as:
(1)
Where
is the time during which work
is performed.
On the other hand, the Work
done by a Force
refers to the release of potential energy from a body that is moved by the application of that force to overcome a resistance along a path. It is a scalar magnitude, and its unit in the International System of Units is the Joule (like energy). Therefore, 1 Joule is the work done by a force of 1 Newton when moving an object, in the direction of the force, along 1 meter (
).
When the applied force is constant and the direction of the force and the direction of the movement are parallel, the equation to calculate it is:
(2)
In this case, we have the following data:



So, let's calculate the work done by Peter and then find how much power is involved:
From (2):
(3)
(4)
Substituting (4) in (1):
(5)
Finally:
Huh? Wheres the question at?