If the friction force and pulling force are equal, then there's no acceleration, and the crate slides at a constant speed.
The correct answer is: <span>X, W, Y, Z
In fact, the elastic potential energy of a spring is given by
</span>
![U= \frac{1}{2}kx^2](https://tex.z-dn.net/?f=U%3D%20%5Cfrac%7B1%7D%7B2%7Dkx%5E2%20)
<span>where k is the spring constant and x is the stretching of the spring with respect to its rest position.
In this problem, all the four springs are stretched by the same distance x. This means that their difference in potential energy is due only to the difference between their spring constant: the larger the spring constant, the greater the energy. Therefore we can list the springs from the one with largest spring constant to the one with smallest constant, and this list corresponds to listing the springs from the one with largest energy to the one with smallest energy:
X, W, Y, Z</span>
Average speed = total distance / total time
total distance = 40 + 20 = 60km
total time taken = 10 + 5 = 15 minutes
Average speed = 60/15 = 4km/min
Answer: d. all of the above
Explanation:
A wildfire can be either naturally occurring or induced by humans for their own benefit. Is likely to exert a negative impact on the wildlife. A fire is likely to spread quickly to the entire canopy cover of the forest trees. This will destroy the availability of food and other resources. Many birds and animals will loose their habitat or shelter. The destruction of the floral species will cause migration of the faunal species to other locations. Therefore, the biodiversity of the region will be lossed.
Weight = (mass) x (gravity).
It always acts downward.
On Earth, the acceleration of gravity is 9.807 m/s².
On the Moon, the acceleration of gravity is 1.623 m/s².
On Earth, the rocket's weight is (0.8kg) x (9.8 m/s²) = 7.84 newtons
On the Moon, the rocket's weight is (0.8kg) x (1.62 m/s²) = 1.3 newtons
The force of the rocket engine acts upward.
Its magnitude is 12 newtons. (From the burning chemicals.
Doesn't depend on local gravity. Same force everywhere.)
Now we have all the data we need to mash together and calculate the
answers to the question. You might choose a different method, but the
machine that I have selected to do the mashing with is Newton's 2nd law
of motion:
Net Force = (mass) x (acceleration).
Since the question is asking for acceleration, let's first solve Newton's law
for it. Divide each side by (mass) and we have
Acceleration = (net force) / (mass) .
On Earth, the forces on the rocket are
(weight of 7.84 N down) + (blast of 12 N up) = 4.16 newtons UP (net)
Acceleration = (4.16 newtons UP) / (0.8 kg) = 5.2 m/s² UP .
On the moon, the forces on the rocket are
(weight of 1.3 N down) + (blast of 12 N up) = 10.7 newtons UP (net)
Acceleration = (10.7 newtons UP) / (0.8 kg) = 13.375 m/s² UP