"Free fall" is the motion of an object when gravity is the ONLY force
acting on it.
In true 'free fall' the speed of an object increases at a constant rate
for the total duration of the fall. The rate of increase, on or near the
Earth's surface, is 9.8 meters per second for each second of fall.
True free fall is almost impossible to observe in everyday life, because
whenever we see anything falling, it's almost always falling through air,
so gravity is NOT the only force acting on it. The friction due to the
motion through air works against the gravitational force. In many cases,
the result is that the object's speed eventually stops increasing and
becomes constant, at a speed often described with the faux technical,
high-fallutin' sounding phrase "terminal velocity". It must be understood
that 'terminal velocity' is NOT a property of gravity or of free fall, but is
only a result of falling through some surrounding stuff that interferes with
the process of true 'free fall'.
Answer:
249.5 minutes
Explanation:
Ali's speed is given by:
where
d is the distance covered
t is the time taken
We know that he can run d = 12 mi in t = 114 min, so he can keep a speed of
The length of a maraton is
L = 26.2 miles
So we can find the time it takes for Ali to complete the marathon as follows
Answer:
the location of 160 N from end E is 25mm
Explanation:
given:
A uniform plank of weight 100 N is 2000 mm long
and rests on a support that is 400 mm from end E
find:
At what distance from E must a 160 N weight be placed in order to balance the plank?
160 N
|---x--->|
100N \|/
======================||======================E
Δ---- 400mm---->|
|<---------------------------- 2000mm --------------------------->|
to determine the location of 160N load in order to balance the plank,
you have to take moment at support Δ.
note:
the 100 N is located at the center of a plank.
the distance of 100N from support = (2000 / 2) - 400 = 600mm
∑moment at Δ = 0
0 = -100 N (600mm) + 160 N (400-x)
0 = -60000 N.mm + 64000 N.mm - 160x N.mm
0 = 4000 - 160x
160x = 4000
x = 4000/160
x = 25 mm
therefore,
the location of 160 N from end E is 25mm
Answer:
Erosion is the wearing away if land by forces such as water and wind. It has created things such as mountain peaks, valleys and coastlines.
B. Titan – is probably the answer
