<span>A person expended 500 newtons to move a full wheelbarrow 30 meters how much work was done?
</span>In physics, a force is said to do work<span> if, when acting, there is a displacement of the point of application in the direction of the force. The work done would be calculated as follows:
</span>
W = F x d = 500 N (30 m) = 15000 J or 15 kJ
The answer is <span>higher than.
</span><span>A sound-producing object is moving toward an observer. The sound the observer hears will have a frequency higher than that actually being produced by the object.
Why?
</span>As the source of the waves is moving toward the observer, each of the successive wave crest<span> is emitted from a position closer to the observer than the previous wave.
Thus each wave takes slightly less time to reach the observer than the previous wave. So, the time between the arrival of successive wave crests at the observer is reduced, increasing the frequency. </span>
It’s light seconds, now don’t mistake it as time
The speed of the tennis ball is 8 km/h when Alana throws the ball behind at the speed of 11 km/h.
<h3>What is the
frame of
reference?</h3>
It is a point from where the motion is observed. The speed changes with the frame of reference.
For the person standstill on the sidewalk, If Alana throw the ball in the front direction, The speed will be,
19+11 = 30 km/h
It Alana just leave the ball, the speed,
19 +0 = 19 km/h
If Alana throws the ball behind her at the speed of 19 km/h. The speed of the ball for a sidewalk observer,
19 +(-19 ) = 0 km/h
Thus, when Aana throw the ball behind the velocity will be negative,
So,
19 + (-11 ) = 8 km/h
Therefore, the speed of the tennis ball is 8 km/h when Alana throws the ball behind at the speed of 11 km/h.
Learn more about Frame of reference:
brainly.com/question/9820962
B) atmosphere pressure, i believe
