Which activity best reflects a muscle movement working against gravity? a lifting the torso during a sit up b lowering the body
2 answers:
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Answer:
D/H =15
Explanation:
- We can find first the peak height H, taking into consideration, that at the maximum height, the ball will reach momentarily to a stop.
- At this point, we can find the value of H, applying the following kinematic equation:
- If vf=0, if we assume that the positive direction is upwards, we can find the value of H as follows:
- We can use the same equation, to find the value of D, as follows:
- In order to find v₁, we can use the same kinematic equation that we used to get H, but now, we know that v₀ = 0.
- When we replace these values in (1), we find that v₁ = -v₀.
- Replacing in (3), we have:
- Solving for D:
- From (2) we know that H can be expressed as follows:
- ⇒ D = 15 * H