Answer:
Explanation:
Given:
- mass of car,
- distance of skidding after the application of brakes,
- coefficient of kinetic friction,
<u>So, the energy dissipated during the skidding of car:</u>
<em>Frictional force:</em>
where N = normal reaction by ground on the car
<em>Now from the work-energy equivalence:</em>
is the dissipated energy.
Answer:
From question (a) and (b) the pendulum motion is perpendicular to the force so the normal force will do no work and the tension in the string of the pendulum will not work
And 
so
c
An example will be a where a stone is attached to the end of a string and is made to move in a circular motion while keeping the other end of the string in a fixed position
d
A dog walking along a surface which has friction, here the frictional force would acting in the direction of the motion and this would do positive work
Explanation:
4 fundamental forses are: strong, electro-magnetic, weak, gravity.
The strong force is the force which can hold nucleus together against enormous forces of repulsion of the protons is strong indeed. In comparasing to electro magnetic force, this force in not an inverse square and it has very short range.
The electro-magnetic force manifests itself as trough the forces between charges(Colubos law) and the magnetic force, both of which are summarized in the Lorentz force law. The electro-magnetic force holds atoms and moleculs together.
The weak force is a force between elementary particles certain processes that take place with low probability, as radio-active beta-decay and collisions between neutrinos and other particles.
The gravity force is the weakest of all 4 fundamental forces. It is the force of attraction between all masses in the universe, especially the attraction of the earth's mass for bodies near its suface. Newton's law of gravity states that gravitational force between two bodies is proportional to the product of their masses and inversely proportional to the square of the distance between them.
Temperature is related to a physical change of a substance because it determines the state of the object via cooling, heating or freezing. To make the concept clear, hear are some examples:-
1. Chocolate melts and turns into liquid form. This is a physical change
2. Water freezes via cooling and forms ice which is in a solid state. This is another physical change
Hope this helped and have a nice day : )
Answer:
4.0 m/s
Explanation:
The motion of the diver is the motion of a projectile: so we need to find the horizontal and the vertical component of the initial velocity.
Let's consider the horizontal motion first. This motion occurs with constant speed, so the distance covered in a time t is
where here we have
d = 3.0 m is the horizontal distance covered
vx is the horizontal velocity
t = 1.3 s is the duration of the fall
Solving for vx,
Now let's consider the vertical motion: this is an accelerated motion with constant acceleration g=9.8 m/s^2 towards the ground. The vertical position at time t is given by
where
h = 4.0 m is the initial height
vy is the initial vertical velocity
We know that at t = 1.3 s, the vertical position is zero: y = 0. Substituting these numbers, we can find vy
So now we can find the magnitude of the initial velocity:
