Which statement best describes gravity
1 answer:
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Answer:
<em>Both energies are equal when the rock has fallen 20 m or equivalently when it is at a height of 20 m.</em>
Explanation:
<u>Potential and Kinetic Energy</u>
The gravitational potential energy is the energy an object has due to its height above the ground. The formula is
Where:
m = mass of the object
g = acceleration of gravity (9.8~m/s^2)
h = height
Note we can also use the object's weight W=mg into the formula:
The kinetic energy is the energy an object has due to its speed:
Where v is the object's speed.
Initially, the object has no kinetic energy because it's assumed at rest.
The W=30 N rock falls from a height of h=40 m, thus:
Since the sum of the kinetic and potential energies is constant:
U' + K' = 1,200 J
Here, U' and K' are the energies at any point of the motion. Since both must be the same:
U' = K' = 600 J
U'=Wh'=600
Solving for h':
Both energies are equal when the rock has fallen 20 m or equivalently when it is at a height of 20 m.
Answer:
a) Tc = 750 [N] ;b) See the explanation below.
Explanation:
To solve this problem, we first need a graphical explanation of this, as well as knowing the corresponding questions. Therefore, a search was carried out in google, in the attached image we will find a graphical description of the problem.
b)
The solution of this type of problem corresponds to the use of Newton's third law, applying static which tells us that the sum of the forces in a system in equilibrium without movement must be equal to zero.
a)
In this way we can find by means of a sum of forces on the y axis equal to zero:
- 850 - 450 + 550 + Tc = 0
Tc = 750 [N]
Answer:
The second fish, X2, is moving faster than the first fish, X1
Explanation:
The given parameters for the equation of motion of the fishes are;
X1 = -6.4 m + (-1.2 m/s)×t
X2 = 1.3 m + (-2.7 m/s)×t
The given equation are straight line equations in the slope and intercept form, where the slope is the speed and in m/s and the intercept is the starting point of swimming of the fishes
For the first fish, the intercept = -6.4 m, the slope = the speed = -1.2 m/s
For the second fish, the intercept = 1.3 m, the slope = the speed = -2.7 m/s
Whereby the fishes are swimming in the opposite direction of the measurement of length, we have;
The magnitude of the speed of the second fish , is larger than the magnitude of the speed of the first fish
Therefore, the second fish, X2, is moving faster than the first fish, X1.