<h3>One reason we should know what the directions of the forces acting on an object is so we can know if we have to add or subtract. same = add together, opposite = subtract from each other. Also if we don't pay attention to the direction the Net force will be wont be accurate. There will be factors that will upset the calculation.So we must know the direction of the two forces because we have to know if we are adding or subtracting and if the answer is accurate. </h3>
<em>I hope this helps!.</em>
Answer:
Explanation:
Acceleration is equal to the change in velocity over the change in time, or
where the change in velocity is final velocity minus initial velocity. Filling in:
Note that I made the backward velocity negative so the forward velocity in our answer will be positive.
Simplifying that gives us:
and then isolating the final velocity, our unknown:
3.0(6.0) = v + 3.0 and
3.0(6.0) - 3.0 = v and
18 - 3.0 = v so
15 m/s = v and because this answer is positive, that means that the car is no longer rolling backwards (which was negative) but is now moving forward.
Answer:
(a) 2.34 s
(b) 6.71 m
(c) 38.35 m
(d) 20 m/s
Explanation:
u = 20 m/s, theta = 35 degree
(a) The formula for the time of flight is given by
![T = \frac{2 u Sin\theta }{g}](https://tex.z-dn.net/?f=T%20%3D%20%5Cfrac%7B2%20u%20Sin%5Ctheta%20%7D%7Bg%7D)
![T = \frac{2 \times 20 \times Sin35 }{9.8}](https://tex.z-dn.net/?f=T%20%3D%20%5Cfrac%7B2%20%5Ctimes%2020%20%5Ctimes%20Sin35%20%7D%7B9.8%7D)
T = 2.34 second
(b) The formula for the maximum height is given by
![H = \frac{u^{2} \times Sin^{2}\theta }{2g}](https://tex.z-dn.net/?f=H%20%3D%20%5Cfrac%7Bu%5E%7B2%7D%20%5Ctimes%20Sin%5E%7B2%7D%5Ctheta%20%7D%7B2g%7D)
![H = \frac{20^{2} \times Sin^{2}35 }{2 \times 9.8}](https://tex.z-dn.net/?f=H%20%3D%20%5Cfrac%7B20%5E%7B2%7D%20%5Ctimes%20Sin%5E%7B2%7D35%20%7D%7B2%20%5Ctimes%209.8%7D)
H = 6.71 m
(c) The formula for the range is given by
![R = \frac{u^{2} \times Sin 2\theta }{g}](https://tex.z-dn.net/?f=R%20%3D%20%5Cfrac%7Bu%5E%7B2%7D%20%5Ctimes%20Sin%202%5Ctheta%20%7D%7Bg%7D)
![R = \frac{20^{2} \times Sin 2 \times 35}{9.8}](https://tex.z-dn.net/?f=R%20%3D%20%5Cfrac%7B20%5E%7B2%7D%20%5Ctimes%20Sin%202%20%5Ctimes%2035%7D%7B9.8%7D)
R = 38.35 m
(d) It hits with the same speed at the initial speed.
Answer:
Explanation:
All the energy in oil, gas, and coal originally came from the sun, captured through photosynthesis.for example when we burn wood to release energy that trees capture from the sun, we burn fossil fuels to release the energy that ancient plants captured from the sun. We can think of this energy as having been deposited in a natural solar power bank over millions of years.
So, in one sense, gasoline-burning cars, coal-burning power plants, and homes heated by natural gas are all solar powered!