How many significant figures are in the number 08.40001<br> 07<br> 3<br> O 6<br> O 5

What is required for equilibrium to exist

creativ13 [48]

They need to touch each other. Equilibrum, is when two things touch that arent the same heat, once they touch, they are equal in temperature, so they need to touch. hope i helped :D

8 0

3 years ago

A person is riding on a Ferris wheel. When the wheel makes one complete turn, the net work done on the person by the gravitation

lara31 [8.8K]

Answer:

0

Explanation:

m = Mass of person

g = Acceleration due to gravity = 9.81 m/s²

d = Vertical height from the ground

F = Force = Weight = mg

Net work done would be

$W_n=W_{up}+W_{down}\\\Rightarrow W_n=Fdcos180+Fdcos0\\\Rightarrow W_n=-mgd+mgd\\\Rightarrow W_n=0$

Hence, the work done on the person by the gravitational force is 0

7 0

3 years ago

A freight car with a mass of 10 metric tons is rolling at 108 km/h along a level track when it collides with another freight car

Rufina [12.5K]

Answer:

20 metric tons

Explanation:

Using the Principle of Conservation of Linear Momentum which states that the total momentum of a system is constant in any direction in which no external force acts.

momentum before collision= momentum after collision

mathematically expressed as

m1u1 + m2u2 = m1v1+m2v2 =0

where:

m1= mass of rolling freight car = 10 metric tons = 10Mg

1 ton = 1000kg= 1Mg

u1 =initial velocity of freight car = 108km/h,

m2 = mass of stationary freight car = ?, this the unknown we are finding

u2 = initial velocity of

m2 = 0, because it is at rest,

v1= final velocity of m1,

v2= final velocity of m2

since they move together in the same direction they share a common final velocity as such

v1=v2= 36km/h

substituting valves in expression give

m1u1 + m2u2 = m1v1 + m2v2= 0

10Mgx 108km/hr + m2 x 0 = 10Mg x 36km/h + m2x36km/h

1080( Mg x km/hr) + 0 = 360 (Mg x Km/h) + 36m2 (km/h)

1080 (Mgx km/hr) - 360(Mg x km/h) = 36m2 (km/h)

720(Mg x km/h) = 36m2 (km/h)

divide both side by 36 (km/h) gives

m2 = 20Mg =20 metric tons

3 0

4 years ago

How does the atmosphere’s interaction with different wavelengths of light help to protect life on earth?

marishachu [46]

Answer:

Ozone layer in the upper atmosphere filters most of the harmful radiations of shorter wavelength. It actually absorbs the hazardous radiations like ultraviolet, gamma rays, x- rays and most of all those having shorter wavelength then the visible light. That's how the earth's atmosphere protects life on earth. But unfortunately, climate change and global warming is causing the depletion of ozone layer which is causing skin related diseases and harming not only the human life but also the plants and animals.

4 0

3 years ago

You punt a ball straight up at 20 m/s. What is the balls hangtime

Natalija [7]

The hang time of the ball is 4.08 s

Explanation:

The ball is in free fall motion: this means that it is acted upon gravity only, so its acceleration is the acceleration of gravity,

$a=g=-9.8 m/s^2$