Change.
Acceleration means going faster
Answer:

Explanation:
As per the formula of thermal expansion we know that

so here we will have



so here change in the length of the rod is given as




Answer:
0.139 rad
Explanation:
We use Snell's law
, where if
is the <em>refractive index</em> of the medium containing the <em>incident ray</em>,
would be the <em>incident angle</em>, and if
is the <em>refractive index</em> of the medium containing the <em>refracted ray</em>,
would be the <em>refraction angle</em>, which we want, so we do:

And finally:

We then insert our values:

Answer:
Option D
490 J
Explanation:
When at a height of 100 am above and released, the ball initially posses only potential energy. When it falls, some potential energy is converted to kinetic energy.
Initial potential energy= mgh where m is the mass, g is the acceleration due to gravity and h is height. Substituting 1 Kg for m, 9.81 for g and 100 m for h then
PE initial = 1*9.81*100= 981 J
At 50 m, PE will be 1*9.81*50=490.5 J
Subtracting PE at 50 m from initial PE we get the energy that has been converted to kinetic energy hence
981-490.5= 490.5 J
Approximately, 490 J
The correct answer is A. In the direction of applied force. This is because acceleration occurs n the direction of applied force according to Newtons second law of motion which states that the acceleration of a body is directly proportional to the applied force and takes place in the direction of force.