Answer:
<em>The ball has 7.35 joules of energy at position B.</em>
<em>The velocity of the ball at position A is 3.13 meter/second</em>
Explanation:
<u>Kinetic and Gravitational Potential Energy</u>
Kinetic energy is the form of energy that an object or a particle has by reason of its motion. An object of mass m and speed v has kinetic energy calculated by:
Gravitational Potential Energy is the form of energy that an object has by reason of its height h relative to a certain reference. It can be calculated as follows:
Where g is the acceleration of gravity.
The figure shows a pendulum with a bob (ball) of mass m=1.5 Kg. When it's pulled to point B, it has a height of h= 0.5 m and set to rest.
The potential energy at that point is:
The ball has 7.35 joules of energy at position B.
When the ball is released, all of the potential energy is transformed into kinetic energy when reaches point A. Thus:
K=7.35 J
From the equation of kinetic energy, we solve for v:
v = 3.13 m/s
The velocity of the ball at position A is 3.13 meter/second
Answer:
In physics, the concept of a frame of reference is used to specify the perspective from which an object or event is observed.
A frame of reference is where the measurements or observations will be made. Because of this, observing an event may be different when changing from one frame of reference to another, because the measurements will be different.
Defining frames of reference is necessary because the movement is relative, it may be that from our perspective or from a frame of reference on earth we are at rest, but seen from a frame of reference in space, we are in motion due that the earth is always moving.
Another example of frames of reference is a moving plane. Seen from the ground an object in the plane moves at the speed at which the plane travels, but if the frame of reference is fixed on the plane, the object is at rest.
Answer:
<h3>The answer is 3.81 kg</h3>
Explanation:
The mass of the dog can be found by using the formula
f is the force
a is the acceleration
From the question we have
We have the final answer as
<h3>3.81 kg</h3>
Hope this helps you
Answer:
v = 31.3 m / s
Explanation:
The law of the conservation of stable energy that if there are no frictional forces mechanical energy is conserved throughout the point.
Let's look for mechanical energy at two points, the highest where the body is at rest and the lowest where at the bottom of the plane
Highest point
Em₀ = U = m g y
Lowest point
= K = ½ m v²
As there is no friction, mechanical energy is conserved
Em₀ =
m g y = ½ m v²
v = √ 2 g y
Where we can use trigonometry to find and
sin 30 = y / L
y = L sin 30
Let's replace
v = RA (2 g L sin 30)
Let's calculate
v = RA (2 9.8 100.0 sin30)
v = 31.3 m / s
Answer:
According to the travellers, Alpha Centauri is <em>c) very slightly less than 4 light-years</em>
<em></em>
Explanation:
For a stationary observer, Alpha Centauri is 4 light-years away but for an observer who is travelling close to the speed of light, Alpha Centauri is <em>very slightly less than 4 light-years. </em>The following expression explains why:
v = d / t
where
- v is the speed of the spaceship
- d is the distance
- t is the time
Therefore,
d = v × t
d = (0.999 c)(4 light-years)
d = 3.996 light-years
This distance is<em> very slightly less than 4 light-years. </em>
