<u>Answer:</u>
2.39 kg
<u>Explanation:</u>
There is conservation of momentum here in this problem so we will use the following problem:
where the mass of the student 
is 48.5 kg,
the mass of the skateboard 
is kg,
the initial speed of the student 
is 4.25 m/s; and
the speed of the student and skateboard 
is 4.05 m/s.
So substituting the given values in the above formula to get:
Therefore, the mass of the skateboard is 2.39 kg.
The property that describes an electromagnetic wave and not a mechanical wave is travels in a a vacuum. That will make the correct answer B. I hope that helps you.
1). Work = (force) x (distance)
Work = (3,000 newtons) x (35 meters) = 105,000 newton-meters = <em>105,000 joules</em>
2). Power = (work) / (time)
Power = (105,000 joules) / (90 seconds)
= 1,166-2/3 joules per second =<em> 1,166 and 2/3 watts</em> .
<em>Note:</em>
That's no ordinary man.
1,166 watts is the same as roughly 1.6 horsepower.
Not too many people can sustain 1 horsepower or more for 90 seconds.
As per given conditions there are two directions along which forces are acting
1. Net force along left direction is given as
2. Net force towards right direction is given as
now since the two forces here in opposite direction so here we will have net force given as
so here net forces must be 440 N towards right
Answer:
Explanation:
You could test effect of oxygen levels on growth of a regular houseplant. You could make the control to be plant grown under regular atmospheric Oxygen level. And for changing variables you could have one plant grow at low oxygen level compared to atmospheric oxygen and another plant to grow at higher levels of oxygen when compared to atmospheric oxygen.
