Answer:
The centripetal force acting on the hammer is 57.14 N.
Explanation:
Given that,
Mass of the hammer, m = 7 kg
Length of the chain, l = 1.3 m
The hammer makes one revolution in 1 s. The length of the chain will be the radius of the circular path. So, the formula of centripetal force is given by :
![F=mr\omega^2](https://tex.z-dn.net/?f=F%3Dmr%5Comega%5E2)
Here, ![\omega=6.28\ rad/s](https://tex.z-dn.net/?f=%5Comega%3D6.28%5C%20rad%2Fs)
![F=7\times 1.3\times 6.28\\\\F=57.14\ N](https://tex.z-dn.net/?f=F%3D7%5Ctimes%201.3%5Ctimes%206.28%5C%5C%5C%5CF%3D57.14%5C%20N)
So, the centripetal force acting on the hammer is 57.14 N. Hence, this is the required solution.
Answer:
The girl is doing work on the ball because the energy in her muscles changed, even though the ball is not displaced.
Explanation:
The complete question is...
Which of these correctly describes whether a girl holding a ball in the same position is doing work on the ball?
-The girl is doing work on the ball because the energy of the ball changed, even though it is not displaced.
-The girl is doing work on the ball because the energy in her muscles changed, even though the ball is not displaced.
-The girl is doing no work on the ball because the ball is not displaced.
-The girl is doing no work on the ball because she is exerting a net force on the ball.
Holding up a ball costs energy, which is used to counter the work that would have otherwise be done on the ball by gravity. Although no physical distance is moved, we should consider the fact that by holding the ball, the girls hand exerts physical force to hold the ball in place. Also, there is a potential gravitational work on the ball due to gravity, but the force exerted by the girls hand does an equivalent of this gravito-potential work in order to counter it and hold the ball in place. All these activities eventually lead to a change in energy in her hand muscle to show that energy is expended.
Answer:
1) 1.08 m/s^2
Explanation:
Acceleration is equal to the change in velocity divided by the time taken:
where
v is the final velocity
u is the initial velocity
is the time taken
In this problem, we have:
- initial velocity: u = 0 (you start from rest)
- final velocity: v = 5.4 m/s
- time taken:
Therefore, the acceleration is
2) -0.54 m/s^2
We can calculate the acceleration to slow down using the same formula as before, but this time the data are as follows:
- initial velocity : u = 5.4 m/s
- final velocity : v = 0 (you come to a stop)
- time taken :
using the same formula, we find
And the negative sign means it is a deceleration.
The main advantage of hydroelectric energy is the fact that it is a renewable energy source (Option C).
<h3>What is hydroelectric energy?</h3>
Hydroelectric energy refers to the energy from water bodies that can be used to generate electricity.
Hydroelectric energy is stored as potential energy and then converted to kinetic motion energy to be converted into electricity.
Hydroelectric energy is renewable because it is indefinitely generated by water bodies in nature.
In conclusion, the main advantage of hydroelectric energy is the fact that it is a renewable energy source (Option C).
Learn more about hydroelectric energy here:
brainly.com/question/3077353
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Answer : The motion of the object is, non-uniform
Explanation :
Uniform motion : It is defined as the movement of an object along a straight line with constant speed. It travels equal distances in equal time interval.
The average speed of an object is similar to the actual speed of an object. The distance-time graph shows a straight line.
Non-uniform motion : It is defined as the movement of an object along a straight line with variable speed. It travels unequal distances in equal time interval.
The average speed of an object is different to the actual speed of an object. The distance-time graph shows a curved line.
The given graph B is a non-uniform motion graph.
Hence, the motion of the object is, non-uniform