These days, scientists all over the world use a standard system of measurements. It's the SI or metric system.
What about scientists in the United States, Liberia, and Burma ?
These three countries are the only ones in the world that haven't
adopted the metric system. What do THEY do ?
Easy. When scientists in those countries are off work, they use the
inches, yards, feet, quarts, miles and gallons that everybody around
them is using. But when they go to work, they use the same metric
system that everyone else in the world is using.
Answer:
The deceleration is 
Explanation:
From the question we are told that
The height above firefighter safety net is 
The length by which the net is stretched is 
From the law of energy conservation

Where
is the kinetic energy of the person before jumping which equal to zero(because to kinetic energy at maximum height )
and
is the potential energy of the before jumping which is mathematically represented at

and
is the kinetic energy of the person just before landing on the safety net which is mathematically represented at

and
is the potential energy of the person as he lands on the safety net which has a value of zero (because it is converted to kinetic energy )
So the above equation becomes

=> 
substituting values

Applying the equation o motion

Now the final velocity is zero because the person comes to rest
So



Answer:
3.46 seconds
Explanation:
Since the ball is moving in circular motion thus centripetal force will be acting there along the rope.
The equation for the centripetal force is as follows -
Where,
is the mass of the ball,
is the speed and
is the radius of the circular path which will be equal to the length of the rope.
This centripetal force will be equal to the tension in the string and thus we can write,

and, 
Thus,
m/s.
Now, the total length of circular path = circumference of the circle
Thus, total path length = 2πr = 2 × 3.14 × 2 = 12.56 m
Time taken to complete one revolution =
=
= 3.46 seconds.
Thus, the mass will complete one revolution in 3.46 seconds.
A and c
Because it defines the boundaries of the system
The relationship between the frequency and wavelength of a wave is given by the equation:
v=λf, where v is the velocity of the wave, λ is the wavelength and f is the frequency.
If we divide the equation by f we get:
λ=v/f
From here we see that the wavelength and frequency are inversely proportional. So as the frequency increases the wavelength decreases.
So the second statement is true: As the frequency of a wave increases, the shorter the wavelength is.