Answer:
a) v₀ₓ = 62.76 m / s, b) θ₁ = 17.6º, θ₂ = 67.0º
Explanation:
We can solve this exercise using the projectile launch ratios
a) Let's find the time it takes for the bullet to reach the water level
y = y₀ + v_{oy} t - ½ g t²
when it reaches the water its height is zero y = 0, as the bullet is fired horizontally its initial vertical velocity is zero
0 = y₀ + 0 - ½ g t²
t =[tex]\sqrt{2y_o/g}[/tex]
t = [tex]\sqrt{2 \ 7 /9.8}[/tex]
t = 1,195 s
now we can calculate the speed with the horizontal movement
x = v₀ₓ t
v₀ₓ = x / t
v₀ₓ = 75.0 / 1.195
v₀ₓ = 62.76 m / s
b) if the speed of the bullets is half of that found
v₀ = 62.76 / 2 = 31.38 m / s
let's write the expressions for the distance
x = v₀ cos θ t
y = y₀ + v_{oy} sin θ t - ½ g t²
t = [tex]\frac{x}{v_o \ cos \theta}[/tex]
we substitute
[tex]0 = y_o + v_o sin \theta \ \frac{x}{v_o \cos \thetay} - 1/2 g \ (\frac{x}{v_o \ cos \theta})^2[/tex]
[tex]0 = y_o + x tan \theta - \frac{1}{2} g \ \frac{x^2}{ v_o^2 \ cos^2 \theta}[/tex]
let's use the identified trigonometry
sec² θ = 1 + tan² θ
sec θ = 1 / cos θ
we substitute
[tex]0 = y_o + x tan \theta - \frac{g x^2}{2 v_o^2} ( 1 + tan^2 \theta)[/tex]
[tex]\frac{g x^2}{2v_o^2} tan^2 \theta - x tan \theta + \frac{gx^2}{2v_o^2} - y_o = 0[/tex]
we change variable
tan θ = H
[tex]\frac{gx^2}{2 v_o^2 } H^2 - x H + \frac{gx^2}{2v_o^2}-y_o =0[/tex]
we subtitle the values
[tex]\frac{9.8 \ 75^2}{2 \ 31.38^2} H^2 - 75 H + \frac{9.8 \ 75^2}{2 \ 31.38^2}-7 =0[/tex]
27.99 H² - 75 H + 20.99 = 0
H² - 2.679 H + 0.75 = 0
we solve the quadratic equation
H = [2.679 ± [tex]\sqrt{2.679^2 - 4 0.75}[/tex]] / 2
H = [2,679 ± 2,044] / 2
H₁ = 0.3175
H₂ = 2.3615
now we can find the angles
H₁ = tan θ₁
θ₁ = tan⁻¹ H₁
θ₁ = tan⁻¹ 0.3175
θ₁ = 17.6º
θ₂ = 67.0º
for these two angles the bullet hits the boat
Do You think History is the most important subject that deserves first place? Do you see a way that learning history could assist you in your future career?
yes
Explanation:
history is an important class and it helps to you understand what went on in the past so that we can learn from our mistakes and help us grow
you describe a friend’s position by including distance, direction, and what other term?
Answer choices:
A. Acceleration
B.displacement
C.Average speed
D. Reference point
PLEASE HELP I NEED THIS IN AN HOUR
Answer:
Acceleration
Explanation:
Answer: Acceleration
Explanation:
When the material in the mantle cools off near the surface then sinks
down towards the core and get heated again and rises back towards the
surface it is called?
Condensation
О
The water cycle
O
Convection currents
О
Apples and Bananas.
PLEASE HELP THIS IS URGENT ITS FOR A TEST
Answer:
convection currents
Explanation:
which particles do not affect the stability of the atom
Electrons are the particle pr4esent inside the atom that does not affect the stability of the atom,
What is radioactivity?The ability of some unstable atoms to emit nuclear radiation spontaneously, typically in the form of alpha or beta particles frequently accompanied by gamma rays, is known as radioactivity.
An overabundance of neutrons or protons can make the nucleus of an atom unstable.
A radioactivity atom will try to become stable by extruding other particles, such as protons or neutrons, or by releasing energy in various ways.
Thus, Electrons are the particle present inside the atom that does not affect the stability of the atom,
To learn more about radioactivity here, refer to the link;
https://brainly.com/question/13950350
#SPJ2
Peter, a 100 kg basketball player, lands on his feet after completing a slam dunk and then immediately jumps up again to celebrate his basket. When his feet first touch the floor after the dunk, his velocity is 5 m/s downward; when his feet leave the floor 0.50 s later, as he jumps back up, his velocity is 4 m/s upward. a. What is the impulse exerted on Peter during this 0.50 s
Answer:
Explanation:
Impulse = change in momentum
Initial momentum = mass x initial velocity = 100 x 5 = 500 kg m/s
final momentum = mass x final velocity = 100 x - 4 = -400 ( - ve sign due to reversal of direction )
change in momentum = final momentum - initial momentum
= - 400 - 500 = - 900 kg m/s .
As it is - ve , it acts upwards .
So magnitude of impulse on Perter = 900 kg m/s
Astronomers study the electromagnetic radiation emitted by distant stars and planets to determine things like: how far away they are, their temperatures and speed, etc. Based on what you learned in this class, explain why the NASA Hubble Space Telescope is better for observing the electromagnetic radiation emitted from stars and planets at 560 km above sea level compared to the Keck telescope in Hawaii, which is 4 km above sea level
Answer:
This same Hawaii telescope, which would be 4 km across water level, can't provide an appropriate version of distanced planetary bodies. A further overview is provided below.
Explanation:
The surface area of that same earth's orbit seems to be approximately 480 km heavy. The atmosphere isn't translucent to the only certain wavelength range of the radioactivity. Not because all-stars, as well as gliders, emit specific wavelengths, but several of them generate ultraviolet as well as infrared. Those same radiations have either been mediated primarily as well as passes through the atmosphere. Due to the Blockage, they can't even be interpreted with such a similar quality unless the telescope would be positioned throughout the portion of the atmosphere.. Why is it harder to stop an elephant accelerating at 1m/s2 than a rabbit accelerating at 1m/s2
(10 Points)
the elephant has more mass
the rabbit is faster
the rabbit has more mass
the elephant is faster
Answer:
this is about momentum p=mv
A, the elephant has more mass
Starting from rest, a wheel with constant angular acceleration turns through an angle of 25 rad in a time t. What will its angular velocity be after 3t?
Answer:
θ = 225 rad
Explanation:
given data
angle = 25 rad
to find out
angular velocity after 3t?
solution
let angular acceleration α in t
θ = ω × t + 0.5 × α × t² ........................1
here ω = 0 (initial velocity )
so put this value here
25 = 0 + 0.5 × α × t² ..........................2
α = 25 ÷ (0.5 t²)
α = 50 ÷ t² .........................3
now here we take in 3t
θ = ω × 3t + 0.5 × α × (3t)²
for ω = 0
θ = 0 + 0.5 × α × 9t²
now put value in eq 2
so
θ = (0.5) × (50 ÷ t²) × (3t)²
θ = 25 × 9
θ = 225 rad
15 points!!:-) Need help ASAP!
When does a compass NOT point towards magnetic north?
A.during a solar eclipse, which changes
Earth's magnetic field.
B. When there is another magnet close by.
C.When there is an unused battery close by.
D. When there is a coil of copper wire close by.
Answer:
b i think so because it makes senes
Answer: When there is another magnet close by.
Explanation: The needle of a compass is itself a magnet, and thus the north pole of the magnet always points north, except when it is near a strong magnet. ... When you take the compass away from the bar magnet, it again points north. So, we can conclude that the north end of a compass is attracted to the south end of a magnet.
Pulling a rubber band back and then letting it fly across the room is an example of
A. converting energy to work
B. converting elastic energy to gravitational
C. converting kinetic energy to potential
Answer:
b
Explanation:
because a elastic band uses elastic energy
How do projectors project the color black?
Answer:
Projectors do not project the color black. This makes sense since black is really the absence of light, and you can't project something that does not exist. When a projector sends a beam of light on to a wall or a projector screen so that an image is formed on the wall or screen, the parts of the image that look black are really a very dim white color (which we sometimes call gray). - wtamu
Answer is:
Projectors do not project the color black.
Violet pulls a rake horizontally on a frictionless driveway with a net force of 2.0 N for 5.0 m.
How much kinetic energy does the rake gain?
Answer:
10 J.
Explanation:
Given that,
Net force acting on the rake, F = 2 N
Distance moved by the rake, d = 5 m
We need to find the kinetic energy gained by the rake. We know that,
Kinetic energy = work done
So,
K = F×d
K = 2 N × 5 m
K = 10 J
So, 10 J of kinetic energy is gained by the rake.
Violet pulls a rake horizontally on a frictionless driveway with a net force of 2.0 N for 5.0 m.
How much kinetic energy does the rake gain?
Answer: 10 J
HELP ASAP PLS
A balloon with a positive charge will stick to a wall that has a negative charge.
What force causes this?
A. Gravity
B. Electric force
C. Magnetic force
D. Air gesistance
Which option tells the forces that influence the movement of earths plates
Answer:
Gravity
Explanation:
A 70 kg Throckmorton was riding his skateboard when a small, but juicy 0.001 kg beetle hits the front of his helmet, splattering, obstructing his view. Who experienced the greatest change in momentum?
Answer:
The beetle
Explanation:
The beetle is correct because of the the force of the Throckmortan was a lot heavier and thus making the beetle feel the force.
Momentum before = momentum after
m₁u₁ + m₂u₂ = m₁v₁ + m₂v₂
(70.0 kg) (3.0 m/s) + (2.0 kg) (3.0 m/s) = (70.0 kg) (3.1 m/s) + (2.0 kg) v
210 kg m/s + 6 kg m/s = 217 kg m/s + (2.0 kg) v
-1 kg m/s = (2.0 kg) v
v = -0.5 m/s
The skateboard's velocity is 0.5 m/s west. Hope I helped and have a good day!
________________________________________________________
前の勢い=後の勢い
m₁u₁+m₂u₂=m₁v₁+m₂v₂
（70.0 kg）（3.0 m / s）+（2.0 kg）（3.0 m / s）=（70.0 kg）（3.1 m / s）+（2.0 kg）v
210 kg m / s + 6 kg m / s = 217 kg m / s +（2.0 kg）v
-1 kg m / s =（2.0 kg）v
v = -0.5 m / s
スケートボードの速度は西に0.5m / sです。私が助けて、良い一日を過ごせることを願っています！
Suppose a cat climbs a tree to a height of 2 meters. If the cat doubles its height to 4 meters, its potential energy will
1)not change
2)reduce to halve
3)double
4)quadruple
6 An object can never have
A. a positive speed.
B. a negative speed.
C. a positive velocity.
D. a negative velocity.
Answer:
B
Explanation:
Speed is the magnitude of the velocity vector, so it can never be negative.
An object can never have a negative velocity. Therefore, option (D) is correct.
What is velocity?Velocity is a vector quantity that describes an object's speed and direction of motion. If an object is moving in a positive direction, it has a positive velocity. If it is moving in the opposite direction, it has a negative velocity.
However, an object can never have a negative speed. Speed is a scalar quantity that describes an object's rate of motion, and it is always positive. The speed of an object can be positive or negative, depending on the direction of its velocity, but the magnitude of its speed is always positive.
Learn more about velocity, here:
https://brainly.com/question/18084516
#SPJ6
Describe the political actions that led to successful conservation in both stories.
Answer:
The political actions that led to successful conservation in both stories were what they call an FC company that makes the forest industry true. They make it out of a factory and it can make it very successful and accomplished.
Explanation:
A wave in which the movement of the wave is perpendicular to the movement of the wave traveling through the medium-compression wave (longitudinal wave)
True or false?
Answer:
I'm rusty sorry if I'm wrong but true?
50 points Two waves combine with constructive interference. What must be true of the
combined wave that forms?
A. It has a lower frequency than that of the original waves.
B. It has a higher amplitude than that of the original waves.
C. It has a higher frequency than that of the original waves.
D. It has a lower amplitude than that of the original waves.
Answer:
it has a higher amplitude than that of the original waves
Explanation:
trust me its right
The two waves combined with constructive interference have a higher amplitude than the original wave.
Which wave has the highest amplitude?High energy waves are characterized by high amplitude. Low energy waves are characterized by their small amplitude. As explained in Lesson 2, wave amplitude is the maximum amount of particle movement on a medium from a resting position.
What are superposition and interference?Superposition is a combination of two waves in the same place. Constructive interference occurs when two identical waves interfere in phase. Destructive interference occurs when two identical waves are exactly out of phase and overlap.
Learn more about higher amplitude waves at
https://brainly.com/question/19036728
#SPJ2
A 15 m uniform ladder weighing 500 N rests against a frictionless wall. The ladder makes a 60° angle with horizontal. (a) Find the horizontal and vertical forces that the earth exerts on the base of the ladder when an 800 N firefighter is 4 m from the bottom. (b) If the ladder is just on the verge of slipping when the firefighter is 9 m up, what is the coefficient of static friction between ladder and ground?
Answer:
a) F₁ = 267.3 N, N₁ = 1300 N, b) μ = 0.324
Explanation:
For this exercise we use the rotational equilibrium condition, we have a reference system is the floor and the anticlockwise rotations as positive, in the adjoint we can see a diagram of the forces
let's use subscript 1 for the ladder and 2 for the firefighter
∑ τ = 0
-W₁ x₁ - W₂ x₂ + N₁ y = 0
N₁ = [tex]\frac{W_1 x_1 + W_2 x_2}{y}[/tex] (1)
the center of mass of the ladder is at its geometric center,
d = L / 2 = 15/2 = 7.5 m
cos 60 = x₁ / d₁
x₁ = d₁ cos 60
x₁ = 7.5 cos 60
x₁ = 3.75 m
for the firefighter d₂ = 4 m
cos 60 = x₂ / d₂
x₂ = d₂ cos 60
x₂ = 4 cos 60 = 2 m
for the fulcrum d₃ = 15 m
sin 60 = y / d₃
y = d₃ sin 60
y = 15 sin 60
y = 13 m
we look for the Normal by substituting in equation 1
N₂ = [tex]\frac{500 \ 3.75 \ + 800 \ 2}{13}[/tex]
N₂ = 267.3 N
now let's use the translational equilibrium relations
X axis
F₁ - N₂ = 0
F₁ = N₂
F₁ = 267.3 N
Axis y
N₁ - W₁ -W₂ = 0
N₁ = W₁ + W₂
N₁ = 500 + 800
N₁ = 1300 N
b) for this case change the firefighter's distance d₂ = 9 m
x₂ = 9 cos 60
x₂ = 4.5 m
we substitute in 1
N₂ = \frac{500 \ 3.75 \ + 800 \ 4.5}{13}
N₂ = 421.15 N
of the translational equilibrium equation on the x-axis
fr = F₁ = N₂
fr = 421.15 N
friction force has the expression
fr = μ N
in this case the reaction of the Earth to the support of the ladder is N1 = 1300N
μ = fr / N₁
μ = 421.15 / 1300
μ = 0.324
how is friction involved in the movement of space
Answer:
Friction can stop or slow down the motion of an object.
Explanation:
The slowing force of friction always acts in the direction opposite to the force causing the motion.
true or false solubility can be used to identify an unknown substance
Answer this and you get 100 points
You better answer it quick though
Answer what? Apologies, but I don't see anything. (。>︿<)
Which of the following is NOT a characteristic of noble gases?
unreactive
odorless
solid at room temperature
colorless
What is the frequency of a wave of a light is with a wavelength of 4 x 10-7 m?
Answer:
7.5 × 10^14 Hz
Velocity of light = 3×10^8m/s
Frequency = (3×10^8)/(4 x 10^-7)
= 7.5 × 10^14 Hz
INT Raindrops acquire an electric charge as they fall. Suppose a 2.0-mm-diameter drop has a charge of 12 pC; these are both very common values. In a thunderstorm, the electric field under a cloud can reach 15,000 N/C, directed upward. For a droplet exposed to this field, how do the magnitude and direction of the electric force compare to those of the weight force
Answer:
W = 2.3 10² [tex]F_{e}[/tex]
Explanation:
The force of the weight is
W = m g
let's use the concept of density
ρ= m / v
the volume of a sphere is
V = [tex]\frac{4}{3}[/tex] π r³
V = [tex]\frac{4}{3}[/tex] π (1.0 10⁻³)³
V = 4.1887 10⁻⁹ m³
the density of water ρ = 1000 kg / m³
m = ρ V
m = 1000 4.1887 10⁻⁹
m = 4.1887 10⁻⁶ kg
therefore the out of gravity is
W = 4.1887 10⁻⁶ 9.8
W = 41.05 10⁻⁶ N
now let's look for the electric force
F_e = q E
F_e = 12 10⁻¹² 15000
F_e = 1.8 10⁻⁷ N
the relationship between these two quantities is
[tex]\frac{W}{F_e}[/tex] = 41.05 10⁻⁶ / 1.8 10⁻⁷
\frac{W}{F_e} = 2,281 10²
W = 2.3 10² [tex]F_{e}[/tex]
therefore the weight of the drop is much greater than the electric force
During a storm, a car traveling on a level horizontal road comes upon a bridge that has washed out. The driver must get to the other side, so he decides to try leaping the river with his car. The side of the road the car is on is18.0 m above the river, while the opposite side is only1.8 m above the river. The river itself is a raging torrent69.0 m wide.Part AHow fast should the car be traveling at the time it leaves the road in order just to clear the river and land safely on the opposite side?Part BWhat is the speed of the car just before it lands on the other side?
Answer:
Part A: The speed the car should be travelling when leaping the river is approximately 37.948 m/s
Part B: The speed of the car just before it lands is approximately 41.92345 m/s
Explanation:
The parameters of the car attempting leaping the river are;
The height of the car over the river = 18 m
The height of the opposite side of the bridge above the river = 1.8 m
The width of the river, x = 69.0 m
Part A
The time, 't' it would take the car to fall from 18 m above the river to 1.8 m above the river is given as follows;
t = √(2·h/g)
Where;
h = The height of the fall = 18 m - 1.8 m = 16.2 m
g = The acceleration due to gravity = 9.8 m/s²
∴ t = √(2×16.2 m/(9.8 m/s²)) = (9/7)·√2 s
The horizontal speed, 'vₓ', with which the car should be travelling at the time it leaves the road in order just to clear the river and land safely on the opposite side is given as follows;
vₓ = x/t = 69.0 m/((9/7)·√2 s) = (161/6)·√2 m/s ≈ 37.948 m/s
The horizontal speed the car should be travelling when leaping the river, vₓ ≈ 37.948 m/s
Part B;
The vertical velocity of the car is given as follows;
[tex]v_y[/tex]² = [tex]u_y[/tex]² + 2·g·h
∴ [tex]v_y[/tex]² =2·g·h = 2 × 9.8 m/s² × 16.200 m = 317.52m²/s²
[tex]v_y[/tex] = √(317.52 m²/s²) = (63/5)·√2 ≈ 17.819 m/s
The magnitude of the speed of the car, 'v', just before it lands is given using Pythagoras' theorem for resultant vectors as follows;
v = √([tex]v_y[/tex]² + vₓ²) = √(317.52 m²/s² +((161/6)·√2 m/s)²) ≈ 41.92345 m/s
The speed of the car just before it lands, v ≈ 41.92345 m/s.
If someone walkes 1000m
in 20min, what is their speed?
Answer:
Distance - 1000m
Time - 20min
Speed - ?
Use the formula of distance ÷ time = speed.
s = d/t
s = 1000m/20min
s = 50 m/min
Hope this helps, thank you !!
What inspired Ronald McNair to do science
Answer:
While working as a staff physicist at hughes Research Laboratories McNair learned that the National Aeronautics and Space Administration (NASA) was looking for scientist to join the shuttle program;)