Answer:
Range formula: R = v^2 sin (2 theta) / g
If theta = 69 deg and v = 15.1
R = 15.1^2 sin 138 / 9,8 = 15.6 m
sin 138 = .669 = sin 42
So a snowball thrown at 21 deg will travel
R = 15.1 * .669^2 / 9.8 = 15.6 m
The second snowball can be thrown at 21 deg to travel the same distance
Vx = V cos theta = 15.1 * cos 69 = 5.41 first snowball
t1 = 15.6 / 5.41 = 2.88 sec
Vx = V cos theta = 15.1 cos 21 = 14.1 m/s
t2 = 15.6 / 14.1 = 1.11 sec
Difference = t1 - t2 = 1.77 sec time delay for second snowball
Answer:
Explanation:
At resonance ω₀L = 1 / ω₀C , L is inductance and C is capacitance .
C = 1 / ω₀²L , ω₀ = 5.1 x 10⁵ . ( given )
voltage over resistance = R I , R is resistance and I is current
voltage over inductance = Iω₀L
R I / Iω₀L = 60 / 40
R / ω₀L = 3 / 2
L = 2 R / 3 ω₀
= 2 x 121 / 3 x 5.1 x 10⁵
= 15.81 x 10⁻⁵
C = 1 / ω₀²L
= 1 / (5.1 x 10⁵)² x 15.81 x 10⁻⁵
= .002432 x 10⁻⁵
= 24.32 x 10⁻⁹ F
Let the angular frequency required be ω
Tan 45 = (ωL - 1 / ωC) / R
ωL - 1 / ωC = R
ω²LC - 1 = R ωC
ω²LC = 1 + R ωC
ω² x 15.81 x 10⁻⁵ x 24.32 x 10⁻⁹ = 1 + 121 x ω x 24.32 x 10⁻⁹
ω² x 384.5 x 10⁻¹⁴ = 1 + 2942.72 x10⁻⁹ω
ω² - 7.65 x 10⁶ ω - 1 = 0
ω = 7.65 x 10⁶
frequency = 7.65 x 10⁶ / 2π
= 1.22 x 10⁶ Hz
<span>In order to answer her question regarding how many students at her high school had summer jobs Nan must follow the procedure given in answer option B: First, randomly select 100 students, then ask them if they have summer jobs. In statistics this method is known as Population Sampling. These 100 students are chosen at random in order to avoid bias - we need them to be representative of the entire high school population.</span>
The ball can't reach the speed of 20 m/s in two seconds, unless you THROW it down from the window with a little bit of initial speed. If you just drop it, then the highest speed it can have after two seconds is 19.6 m/s .
If an object starts from rest and its speed after 2 seconds is 20 m/s, then its acceleration is 20/2 = 10 m/s^2 .
(Gravity on Earth is only 9.8 m/s^2.)