2. (9 points) A car starts from 10 mph and accelerates along a level road, i.e., no grade change. At 500 ft from its starting po
1 answer:
Answer:
a) t = 11.2 s
b) v = 70.5 mph
Explanation:
a)
- Since we need to find the time, we could use the definition of acceleration (rearranging terms) as follows:
- where vf = 50 mph, and v₀ = 10 mph.
- However, we still lack the value of a.
- Assuming that the acceleration is constant, we can use the following kinematic equation:
- Since we know that Δx = 500 ft, we could solve (2) for a.
- In order to simplify things, let's first to convert v₀ and vf from mph to m/s, as follows:
- We can do the same process with Δx, from ft to m, as follows:
- Replacing (3), (4), and (5) in (2) and solving for a, we get:
- Replacing (6) in (1) we finally get the value of the time t:
b)
- Since the acceleration is constant, as we know the displacement is another 500 ft (152.4m), if we replace in (2) v₀ by the vf we got in a), we can find the new value of vf, as follows:
- If we convert vf again to mph, we have:
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Answer:
<h2>206.67N</h2>Explanation:
The sum of force along both components x and y is expressed as;
The magnitude of the net force which is also known as the resultant will be expressed as
To get the resultant, we need to get the sum of the forces along each components. But first lets get the acceleration along the components first.
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