Answer:
3 m/s^2
Explanation:
acceleration= Change in velocity/time
= 30-0 / 10
= 30/10
=3 m/s^2
Answer:
W = 8.01 × 10^(-17) [J]
Explanation:
To solve this problem we need to know the electron is a subatomic particle with a negative elementary electrical charge (-1,602 × 10-19 C), The expression to calculate the work is given by:
W = q*V
where:
q = charge = 1,602 × 10^(-19) [C]
V = voltage = 500 [V]
W = work [J]
W = 1,602 × 10^(-19) * 500
W = 8.01 × 10^(-17) [J]
Answer:
the outer covering of a bird is usually for camoflauge (idk how to spell) or to attract mates and the outer part of a tree is used for protection i think, correct me if im wrong ;-;
Explanation:
<span>Avogadro's number
represents the number of units in one mole of any substance. This has the value
of 6.022 x 10^23 units / mole. This number can be used to convert the number of
atoms or molecules into number of moles.
</span>1.83 moles K (6.022 x 10^23 atoms / mole ) = 1.10 x 10^24 atoms K
Answer:
(a) ![W_c=127.008 J](https://tex.z-dn.net/?f=W_c%3D127.008%20J)
(b) ![W_g=148.176 J](https://tex.z-dn.net/?f=W_g%3D148.176%20J)
(c) K.E. = 21.168 J
(d) ![v=3.4293m.s^{-1}](https://tex.z-dn.net/?f=v%3D3.4293m.s%5E%7B-1%7D)
Explanation:
Given:
- mass of a block, M = 3.6 kg
- initial velocity of the block,
![u=0 m.s^{-1}](https://tex.z-dn.net/?f=u%3D0%20m.s%5E%7B-1%7D)
- constant downward acceleration,
![a_d= \frac{g}{7}](https://tex.z-dn.net/?f=a_d%3D%20%5Cfrac%7Bg%7D%7B7%7D)
That a constant upward acceleration of
is applied in the presence of gravity.
∴![a=- \frac{6g}{7}](https://tex.z-dn.net/?f=a%3D-%20%5Cfrac%7B6g%7D%7B7%7D)
- height through which the block falls, d = 4.2 m
(a)
Force by the cord on the block,
![F_c= M\times a](https://tex.z-dn.net/?f=F_c%3D%20M%5Ctimes%20a)
![F_c=3.6\times (-6)\times\frac{9.8}{7}](https://tex.z-dn.net/?f=F_c%3D3.6%5Ctimes%20%28-6%29%5Ctimes%5Cfrac%7B9.8%7D%7B7%7D)
![F_c=-30.24 N](https://tex.z-dn.net/?f=F_c%3D-30.24%20N)
∴Work by the cord on the block,
![W_c= F_c\times d](https://tex.z-dn.net/?f=W_c%3D%20F_c%5Ctimes%20d)
![W_c= -30.24\times 4.2](https://tex.z-dn.net/?f=W_c%3D%20-30.24%5Ctimes%204.2)
We take -ve sign because the direction of force and the displacement are opposite to each other.
![W_c=-127.008 J](https://tex.z-dn.net/?f=W_c%3D-127.008%20J)
(b)
Force on the block due to gravity:
![F_g= M.g](https://tex.z-dn.net/?f=F_g%3D%20M.g)
∵the gravity is naturally a constant and we cannot change it
![F_g=3.6\times 9.8](https://tex.z-dn.net/?f=F_g%3D3.6%5Ctimes%209.8)
![F_g=35.28 N](https://tex.z-dn.net/?f=F_g%3D35.28%20N)
∴Work by the gravity on the block,
![W_g=F_g\times d](https://tex.z-dn.net/?f=W_g%3DF_g%5Ctimes%20d)
![W_g=35.28\times 4.2](https://tex.z-dn.net/?f=W_g%3D35.28%5Ctimes%204.2)
![W_g=148.176 J](https://tex.z-dn.net/?f=W_g%3D148.176%20J)
(c)
Kinetic energy of the block will be equal to the net work done i.e. sum of the two works.
mathematically:
![K.E.= W_g+W_c](https://tex.z-dn.net/?f=K.E.%3D%20W_g%2BW_c)
![K.E.=148.176-127.008](https://tex.z-dn.net/?f=K.E.%3D148.176-127.008)
K.E. = 21.168 J
(d)
From the equation of motion:
![v^2=u^2+2a_d\times d](https://tex.z-dn.net/?f=v%5E2%3Du%5E2%2B2a_d%5Ctimes%20d)
putting the respective values:
![v=\sqrt{0^2+2\times \frac{9.8}{7}\times 4.2 }](https://tex.z-dn.net/?f=v%3D%5Csqrt%7B0%5E2%2B2%5Ctimes%20%5Cfrac%7B9.8%7D%7B7%7D%5Ctimes%204.2%20%7D)
is the speed when the block has fallen 4.2 meters.