Answer:
Explanation:
From the second law of Newton movement laws, we have:
, and we know that a is the acceleration, which definition is:
, so:
The next step is separate variables and integrate (the limits are at this way because at t=0 the block was at rest (v=0):
(This is the indefinite integral), the definite one is:
Answer:
b. melting
Explanation:
it is made of sediments and that is not necessary
Answer:
(a) t = 1.14 s
(b) h = 0.82 m
(c) vf = 7.17 m/s
Explanation:
(b)
Considering the upward motion, we apply the third equation of motion:
where,
g = - 9.8 m/s² (-ve sign for upward motion)
h = max height reached = ?
vf = final speed = 0 m/s
vi = initial speed = 4 m/s
Therefore,
<u>h = 0.82 m</u>
Now, for the time in air during upward motion we use first equation of motion:
(c)
Now we will consider the downward motion and use the third equation of motion:
where,
h = total height = 0.82 m + 1.8 m = 2.62 m
vi = initial speed = 0 m/s
g = 9.8 m/s²
vf = final speed = ?
Therefore,
<u>vf = 7.17 m/s</u>
Now, for the time in air during downward motion we use the first equation of motion:
(a)
Total Time of Flight = t = t₁ + t₂
t = 0.41 s + 0.73 s
<u>t = 1.14 s</u>
3 hours and 40 minutes is equivalent to 3.667 hours. If a woman must have run another marathon (of 26.2 miles) within that time, then her minimum average speed in mph can be calculated by dividing the distance by time:
26.2 miles / 3.667 hours = 7.145 miles per hour