Answer:
B) t = 1.83 [s]
A) y = 16.51 [m]
Explanation:
To solve this problem we must use the following equation of kinematics.

where:
Vf = final velocity = 0
Vo = initial velocity = 18 [m/s]
g = gravity acceleration = 9.81 [m/s²]
t = time [s]
Note: the negative sign in the above equation means that the acceleration of gravity is acting in the opposite direction to the motion.
A) The maximum height is reached when the final velocity of the ball is zero.
0 = 18 - (9.81*t)
9.81*t = 18
t = 18/9.81
t = 1.83 [s], we found the answer for B.
Now using the following equation.

where:
y = elevation [m]
Yo = initial elevation = 0
y = 18*(1.83) - 0.5*9.81*(1.83)²
y = 16.51 [m]
<span>This is because Helium
has two valence electrons compared to Hydrogen which has only one. Helium has
more energy levels for an electron to jump thus more spectral lines to occur.
The spectral lines relating to each change of energy level would be more
grouped together and hence the greater chance of them falling in the visible
range.</span>
Answer:
115, 80, 15m
Explanation
t1 = 14s
t2 = 18s
change in time = 4s (18-14)
r(final) = r(initial) + (average velocity) x (change in time)
multiply the average velocity with the change in time
= (4, 0, -3) x 4 = 16, 0, -12
now we'll add this value to the initial position of the car
(99, 80, 27)m + (16, 0, -12)m = (115, 80, 15)m
Answer:
B. Northern Canada
Explanation:
A continental polar air mass can form over the land during the winter months. In the Northern Hemisphere, it originates in northern Canada or Alaska. As it moves southward, it brings dry weather conditions to the United States. Temperature and humidity levels are both low. Hope this helps :)
Answer:
The second is correct.
Explanation:
Try with a magnet and experiment. You'll find out