A light-year is how astronomers measure distance in space.
-Light can travel 300,000 kilometres in one seconds!
Light year is the distance that light travel can travel in one year.
-Light can also travel 9,00,000,000,000 kilometers.
-One light is about 10 trillion km.
-Almost 300 years ago ,a Danish scientist named olaus roemer,was the fist man to estimate the distance light travels in a year -and using that he figure out the approximate speed of light!
Energy and momentum are always conserved. Kinetic energy is not conserved in an inelastic collision though. And that is because it is converted to another form of energy
Answer
i'm not 100% sure but 1764
Explanation:
Work done = gravitational potential energy
Gravitational potential energy = mass(kg) × height(m) × gravitational field strength(N/kg)
We can assume that the student is on earth so the gravitational field strength is 9.8N/kg
So work done = 60 × 3×9.8
=1764
(if you need help calculating power but if you do just divide your answer by 12 and you will get 147)
<u>Answer:</u>
<em>Resultant of two vectors having opposite direction is the difference of the two displacements having the same direction as the larger vector.
</em>
<u>Explanation:</u><u>
</u>
Resultant of two vectors is obtained by performing the vector addition operation. When the directions of both vectors are same the resultant’s direction will also be the same as the inputs. When two vectors have opposite directions, one direction will be taken positive making one vector positive and the other negative.
By performing addition of a positive and negative number we are actually taking the difference between both. Thus performing vector addition of two vectors with opposite directions is equivalent to finding the difference between the vectors. Consider a system consisting of a solid block, on which two forces F1 and F2 act in the opposite direction.
One force will be considered positive and the other is considered negative. The resultant is given by the difference of two force vectors. Displacement of the block will be in the direction of the greater force.
