Answer:
c. absorbs all the energy that strikes it.
Explanation:
<em>An ideal black body is an object that absorbs every light energy (irrespective of the wavelength and direction) that strikes it without reflecting any in return. </em>
<em>Such objects or bodies usually appear perfectly black and will only emit radiation when heated to a very high temperature.</em>
Answer:
(a) 2400N
(b) Yes
Explanation:
(a) Mass (m) = 1.5kg, initial speed (v) = 4m/s, time (t) = 2.5milliseconds = 2.5/1000 = 0.0025seconds
F = mv/t = (1.5×4)/0.0025 = 6/0.0025 = 2400N
(b) The force would be different because the mass of the two hands and forearms is 3kg (2 × 1.5kg = 3kg)
Mass extinction occur from natural disasters, such as a n asteroid hitting earth or a volcano errupting and spread ash everywhere.
It makes sense to measure geologic time between mass extinctions because after each mass extinction, there is almost no life left and the few left have to repopulate, which may lead way to new mutations and new varieties of plants and animals.
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Acceleration = force / mass = 20 / 2 = 10 m/s^2
The relation between temperature and pressure is called the "equation of state of the gas". or "Hydrostatic equilibrium in ordinary star". Take for example a balloon, it will have a larger spherical shape, if the pressure inside exerted by the gas on a wall of a balloon balance the inward force exerted by the outside atmospheric pressure. In a dying star which is being compressed by gravity, the gas is being squeezed so the molecules is moving rapidly, resulting to a very high temperature, and this provide a balance that counteract or balances the compressive force of gravity. The very high temperature inside the star is needed to balance the force of gravity, and it is provide by "nuclear fusion energy" or else the star would collapse under the force of gravity. Depending on the size or mass of the star, it will either become, a "neutron star" or a "black hole".
