Answer:
Unit of energy is kg-m/s or Joules.
Explanation:
The mass- energy relationship in physics is given by :

Where
m is the mass of the object
c is the speed of light
The SI unit of m is kilogram while the SI unit of c is as same as speed of light i.e. m/s. So, the unit of energy is kg-m/s. It is also equivalent to Joules.
So, the SI unit of energy is kg-m/s or Joules. Hence, this is the required solution.
Answer:
Aluminium
Explanation:
Aluminium has the least resistance since It has 3 free electrons per atom. Its resistivity is low compared to other metals provided in the choices (gold, nichrome, tungsten). Low resistivity of metals means a high conductance of the metal referred to.
Answer:
f = 55mm, h ’= -9.89 cm
f = 200 mm, h ’= 42.5 cm
Explanation:
For this exercise let's start by finding the distance to the image, using the equation of the constructor

where f is the focal length, p and q are the distances to the object and image, respectively
lens with f₁ = 55mm = 0.55cm
=
= 1.718
q₁ = 0.582 m
lens with f₂ = 200mm = 2m
=
= 0.4
q₂ = 2.5 m
the magnification of a lens is given by
m =
h ’=
let's calculate for each lens
f = 55mm
h '= - 0.582 / 10 1.7
h ’= 0.0989 m
h ’= -9.89 cm
f = 200 mm
h '= - 2.5 / 10 1.7
h ’= -0.425 m
h ’= 42.5 cm
The negative sign indicates that the image is real and inverted
In projectile motion the horizontal component is not affected by gravity. You split the motion in horizontal and vertical motion. The horizontal will be an uniform motion, with v being constant. While the vertical will be an uniform accelerated motion, with the acceleration being the gravity.
Answer:
The correct option is a
Explanation:
This question seeks to test a general rule in physics (on charges) which states that <u>like charges repel but unlike charges attract</u>. This means that, a negatively charged substance will repel or not attract another negatively charged material and the same applies to a positively charged substance also. However, a <u>negatively charged substance will attract a positively charged material and vice versa,</u> hence only a negatively charged rod will attract a positively charged hanging ball.