Answer:
velocity at the top: 0 m/s
acceleration at the top: -9.8 m/s²
Explanation:
Assuming up is positive and down is negative;
The velocity of the ball at the top of its path will be 0 m/s and the acceleration will be negative.
The velocity is 0 m/s because the ball does not move at the top of its path, and it switches from a positive velocity to a negative velocity. It must go through 0 in order to go from positive to negative.
The acceleration, however, is always negative no matter where the ball is in its motion. This negative acceleration causes the ball to slow down as it reaches the top, and speed up as it reaches the bottom.
<u>Think about it:</u> If there wasn't a negative acceleration, and it was instead 0, the ball would never come back down and instead keep going in a straight line.
Answer:
a) v = 0.9167 m / s, b) A = 0.350 m, c) v = 0.9167 m / s, d) A = 0.250 m
Explanation:
a) to find the velocity of the wave let us use the relation
v = λ f
the wavelength is the length that is needed for a complete wave, in this case x = 5.50 m corresponds to a wavelength
λ = x
λ = x
the period is the time for the wave to repeat itself, in this case t = 3.00 s corresponds to half a period
T / 2 = t
T = 2t
period and frequency are related
f = 1 / T
f = 1 / 2t
we substitute
v = x / 2t
v = 5.50 / 2 3
v = 0.9167 m / s
b) the amplitude is the distance from a maximum to zero
2A = y
A = y / 2
A = 0.700 / 2
A = 0.350 m
c) The horizontal speed of the traveling wave (waves) is independent of the vertical oscillation of the particles, therefore the speed is the same
v = 0.9167 m / s
d) the amplitude is
A = 0.500 / 2
A = 0.250 m
Helium (He) does not have the same number of valence electrons as other elements in its group.
The periodic table is divided into groups with the last number of the group coinciding with the number of electrons that an element in the group has in its outermost or valence shell.
Helium is in group 18 which means that it should have the same number of valence electrons as :
- Neon
- Argon
- Krypton
- Xenon and,
- Radon
Yet Helium only has 2 valence electrons. We can therefore conclusively say that Helium does not have the same number of valence electrons as other elements in its group.
<em>More information is available at brainly.com/question/20944279. </em>
Answer
t = 367.77 s = 6.13 min
Explanation:
According to the law of conservation of energy:
where,
P = Electric Power of Heater = 300 W
t = time required = ?
m_g = mass of glass = 300 g = 0.3 kg
m_w = mass of water = 250 g = 0.25 kg
C_g = speicific heat of glass = 840 J/kg.°C
C_w = specific heatof water = 4184 J/kg.°C
ΔT_g = ΔT_w = Change in Temperature of Glass and water = 100°C - 15°C
ΔT_g = ΔT_w = 85°C
Therefore,
<u>t = 367.77 s = 6.13 min</u>
Answer:
26.9 Pa
Explanation:
We can answer this question by using the continuity equation, which states that the volume flow rate of a fluid in a pipe must be constant; mathematically:
(1)
where
is the cross-sectional area of the 1st section of the pipe
is the cross-sectional area of the 2nd section of the pipe
is the velocity of the 1st section of the pipe
is the velocity of the 2nd section of the pipe
In this problem we have:
is the velocity of blood in the 1st section
The diameter of the 2nd section is 74% of that of the 1st section, so
The cross-sectional area is proportional to the square of the diameter, so:
And solving eq.(1) for v2, we find the final velocity:
Now we can use Bernoulli's equation to find the pressure drop:
where
is the blood density
are the initial and final pressure
So the pressure drop is:
