Use kinematic equations to solve:
1) yf = yo + vo*t + 1/2at²
yf = final height
yo = initial height
vo = initial velocity
a = acceleration
t = time
yf - yo = vo*t + 1/2at²
yf - yo = h
vo = 0
Thus,
h = 1/2at²
h = 1/2(9.8)(12)² = 705.6 m
2) vf = vo + at
vo = 0
Thus,
vf = at
vf = (9.8)(12) = 117.6 m/s
Answer:
Surface tension in water
Friction between tires and pavement
Dissolution of salt in water
Explanation:
Surface tension in water: It is due to the electrostatic force of attraction (cohesive force) between water molecules.
Friction between tires and pavement: It is due to the attractive force between tires and pavement.
Dissolution of salt in water: The ions of
and
separate due to the strong attraction of water molecules.
Answer:
v_average = 15 m / s
Explanation:
The average speed can be found in two ways,
* taking the distance traveled and divide it by the time spent
* taking the velocities in each time interval and then finding the weighted average by the time fraction
v_average = 1 / t_total ∑
vi ti
Let's apply this last equation
Total time is
t = t₁ + t₂
t = 10 + 10 = 20 min
v_average = 10/20 10 + 10/20 20
v_average = 10/2 + 20/2
v_average = 15 m / s
I believe the k value represents the D. Stiffness of the spring.
Answer:
Surface tension.
Explanation:
Water has this thing called surface tension, where the water, most of the time, is hard to split.
A few examples of surface tension in action:
- If you spill some water, you can see that they seem to connect together as if they were magnetic.
- You can put around 20-30 drops of water on average on a penny. This shows that water has better surface tension than other liquids, like oil, that can the penny can only hold around 10-15.
- Lastly, water bugs (which are kind of like mosquitos) can actually stay on top of the water, because they do not break the surface tension of it.
Hope this helps you!