<span>What you need to do while answering this questions, is ask yourself what has cells - only if a thing has cells can you see those cells under a microscope. Objects of animal and plant origin have cells, so blood, plant and cork (made of tree bark) can have cells, and a box too, if it's made of wood. So we can''t exclude any answers based on this. We must then know the story of Robert Hook - and it was in fact a cork. He did this discovery around 1655. At the time his main interest was the microscope rather than the cork, and he used to cork to demonstrate the function of the microscope. The correct answer is CORK.</span>
Answer:
e = 0.46 m
Explanation:
From the laws of friction, frictional force, F is proportional to normal reaction, R.
F₁ = μR
where μ is coefficient of friction; R = mg and g = 9.8 ms⁻²
Also, from Hooke's law, extension, e, in an elastic spring is proportional to applied force.
F₂ = Ke
where K is force constant of the spring
Since the box is just about to move, the coefficient of friction involved is static friction.
The force on the spring equals the frictional force experienced by the box the box; F₁ = F₂
Ke = μR
e = μR/K
where μ = 0.65; R = 18 kg * 9.8 ms⁻²; K = 250 N/m
e = (0.65 * 18 * 9.8)/250
e = 0.46 m
Answer:
4.87×10⁶ kJ
1.63×10⁸ Joules
1015 $
Explanation:
a. To convert the units, you can use this conversion factor:
1 kWh = 3.6×10⁶J
1355 kWh . 3.6×10⁶J / 1 kWh = 4.871×10⁹ J
Now we convert to kJ → 4.87×10⁹ J . 1 kJ/1000J = 4.87×10⁶ kJ
b. In 30 days, we used 1355 kWh so, let's determine the use by day
1355 kWh / 30 day = 45.2 kWh
Now we convert the 45.2 kWh to Joules → 45.2 kWh . 3.6×10⁶J / 1 kWh =
1.63×10⁸ Joules
c. We can make a rule of three, for this:
1 kWh costs $0.749
1355 kWh will pay (1355 . 0.749) / 1 = 1015 $
D) they will all hit the ground at the same time. In the context that there is no air resistance and each object is in free fall, then they will have the same acceleration rate.
Answer:
Centrifugal force
Explanation:
In Space, It is in a way possible create an " artificial gravity" just by spinning the aircraft or space station. On spinning the space station the inhabitants feel an outward force or the centrifugal force, this outward force when equivalent to gravitational force is able to stimulate gravity.