The heat pump is a thermal machine that takes heat from a cold space and transfers it to a hotter one thanks to a work provided from the outside, that is, it does exactly the same as the refrigerating machine, the only thing that changes is the objective (In the refrigerating machine the objective is to cool and keep the cold space cold. The heat pump, however, aims to provide heat and keep the hot space warm)
Therefore the correct answer is A. <em>A heat pump uses work to transfer energy by heat from a colder environment to a warmer environment.</em>
Use the law of universal gravitation, which says the force of gravitation between two bodies of mass <em>m</em>₁ and <em>m</em>₂ a distance <em>r</em> apart is
<em>F</em> = <em>G m</em>₁ <em>m</em>₂ / <em>r</em>²
where <em>G</em> = 6.67 x 10⁻¹¹ N m²/kg².
The Earth has a radius of about 6371 km = 6.371 x 10⁶ m (large enough for a pineapple on the surface of the earth to have an effective distance from the center of the Earth to be equal to this radius), and a mass of about 5.97 x 10²⁴ kg, so the force of gravitation between the pineapple and the Earth is
<em>F</em> = (6.67 x 10⁻¹¹ N m²/kg²) (1 kg) (5.97 x 10²⁴ kg) / (6.371 x 10⁶ m)²
<em>F</em> ≈ 9.81 N
Notice that this is roughly equal to the weight of the pineapple on Earth, (1 kg)<em>g</em>, where <em>g</em> = 9.80 m/s² is the magnitude of the acceleration due to gravity, so that [force of gravity] = [weight] on any given planet.
This means that on this new planet with twice the radius of Earth, the pineapple would have a weight of
<em>F</em> = <em>G m</em>₁ <em>m</em>₂ / (2<em>r</em>)² = 1/4 <em>G m</em>₁ <em>m</em>₂ / <em>r</em>²
i.e. 1/4 of the weight on Earth, which would be about 2.45 N.
Explanation:
Radius of a charged particle is given by
r=mv / Bq
= k/ q
where k = m v / B is a constant.
i.e. more is the magnitude of charge, less is the radius.
(inversely proportional)
From the diagram r_3 > r_2 > r_1 (more the curvature, less is the radius)
( although drawing is not given i am assuming the above order, however, one can change the order as per the diagram. The concept used remains the same)
therefore, q_1 > q_2 > q_3
.
Answer:
10 N, north-east
Explanation:
The two forces applied on the object are perpendicular to each other, so we can find the magnitude of their resultant by using the Pythagorean theorem:
The direction of the force instead is given by
where F_n is the force pointing north, and F_e is the force pointing east, and the angle is measured with respect to the east direction. Substituting,
Answer:
Secant line is a straight line which joins the two points of functions and it also represents the slope between two points.
Explanation:
Secant line is also known as average rate of change of functions between two points and also called slope.
In mathematical form,
Secant line = average rate of change = slope
Slope m = y/x