<h2>a) Average velocity in first 4 seconds is 64 ft/s upward</h2><h2>b) Average velocity in second 4 seconds is 63.5 ft/s downward</h2>
Explanation:
a) Given S(t) = 76 + 128t − 16t²
s(0) = 76 + 128 x 0 − 16 x 0² = 76 ft
s(4) = 76 + 128 x 4 − 16 x 4² = 332 ft
Displacement in 4 seconds = 332 - 76 = 256 ft
Time = 4 - 0 = 4 s
Average velocity in first 4 seconds is 64 ft/s upward
a) Given S(t) = 76 + 128t − 16t²
s(4) = 76 + 128 x 4 − 16 x 4² = 332 ft
s(8) = 76 + 128 x 8 − 16 x 8² = 78 ft
Displacement in 4 seconds = 78 - 332 = -254 ft
Time = 4 - 0 = 4 s
Average velocity in second 4 seconds is 63.5 ft/s downward
Answer:
Δd = 
Explanation:
As 
, when the car is making full stop, 
. 
. Therefore,
Apply the same formula above, with 
and 
, and the car is starting from 0 speed, we have
As 
. After 
, the car would have traveled a distance of
Hence 
As 
we can simplify 
After t time, the train would have traveled a distance of 
Therefore, Δd would be 
Answer:
1. 37.8J
2. 18 Billion Joules, 18 Gigajoules
3. 9.81 Billion Joules, 9.81 Gigajoules
Explanation:
Use the formulas provided,
KE=(1/2)mv^2 and PE=mgh, noting that g=9.81
Friction is causing the skateboard to stop rolling.
Answer:
When scientists have a question, they form a hypothesis, <em>which</em><em> </em><em>is</em><em> </em><em>an</em><em> </em><em>idea</em><em> </em><em>that</em><em> </em><em>may</em><em> </em><em>be</em><em> </em><em>proved</em><em> </em><em>or</em><em> </em><em>disproved</em><em> </em><em>by</em><em> </em><em>an</em><em> </em><em>experiment</em><em>.</em>
