The efficiency of a machine indicates how well its input energy is converted to useful output energy or work. It is a major factor in the usefulness of a machine and is the fraction or percentage of the output divided by the input.
According to the Law of Conservation of Energy, the total output energy or work must equal the total input energy. However, some of the input energy does not contribute to the output work and is lost to such things as friction and heat.
Examples of machine efficiency include a lever, automobile, and perpetual motion machine.
Answer:
<em>The sprinter traveled a distance of 7.5 m</em>
Explanation:
<u>Motion With Constant Acceleration
</u>
It's a type of motion in which the rate of change of the velocity of an object is constant.
The equation that rules the change of velocities is:
Where:
a = acceleration
vo = initial speed
vf = final speed
t = time
The distance traveled by the object is given by:
Using the equation [1] we can solve for a:
The sprinter travels from rest (vo=0) to vf=7.5 m/s in t=2 s. Computing the acceleration:
Now calculate the distance:
The sprinter traveled a distance of 7.5 m
To solve this problem, we will define speed as the amount of distance traveled per unit of time. We will clear the value of time and in parallel we will convert the Units to an international system to facilitate the calculation since we know the speed of light in a vacuum. The speed defined in terms of distance and time would be
The speed of light in a vacuum is and 1ft is equivalent to , so the estimated time would be
We know that 1 second is equivalent to , therefore
Therefore the time is 1.02ns
Hi Maria.
The formula for finding the mass of the object is M = F/A, or the force divided by the acceleration. Since we have our force and acceleration, we are ready to solve!
M = 350 / 10.
M = 35.
The unit of measurement for mass is kg, so your answer is going to be
35 kg.
I hope this helps!
Answer:
2.42 seconds
Explanation:
Assume that air resistance is negligible, use trigonometry to find the vertical component of the velocity by using trigonometry:
<span>31⋅<span>sin50</span>=23.7</span>
Where 31 <span>m<span>s<span>−1</span></span></span> is the hypotenuse and by using sin to get the opposite component (vertical velocity) of the trajectory.
Now comes the use of the formula:
v = u + at
where v is the final velocity (0 <span>m<span>s<span>−1</span></span></span>), u is the initial velocity (31 <span>m<span>s<span>−1</span></span></span> ), a is the acceleration of gravity (9.81 <span>m<span>s<span>−2</span></span></span>) and t is the time it takes to arrive at the top of the trajectory.
By making t as the subject:
<span>t=<span><span>v−u</span>a</span></span>
You can calculate the value of t:
<span><span><span>0−23.7</span><span>−9.81</span></span>=2.42</span> (to 3 significant figures)
Better way to see it:
<span><span><span>0−<span>(31⋅<span>sin50</span>)</span></span><span>−9.81</span></span>=2.421</span> (to 4 significant figures)
Note: You must remember that you are dealing with velocity, not speed . Since velocity is a vector quantity, you must select the direction at which values will be positive. In my example, I set my upward direction as the positive value while my downward vectors as negative value (a, acceleration, 9.81 <span>m<span>s<span>−1</span></span></span>).