Answer:
-0.55m/s
Explanation:
Given that: For the boy
Weight = 745N
Velocity = +0.35 m/s
Mass of the boy = ?
g = 9.81m/s^2
W = mg
745 = m×9.81
m = 75.94kg
For the girl
Given that:
Weight = 477 N
g = 9.81m/s^2
m = ?
W = mg
477 = m×9.81m/s^2
m = 48.62kg
To solve for the v of the girl, the two has to add up
48.62kg×v + 75.94kg×+0.35 m/s = 0
48.62v + 26.579 = 0
48.62v = - 26.579
v = -26.579/48.62
v = -0.5466
v = -0.55m/s
Hence, the velocity of the girl is -0.55m/s.
The negative sign is as a result of the two of them moving is opposite direction.
true or false
Almost all of Earth's atmosphere is created through the process of photosynthesis.
Answer:
true
Explanation:
I believe the answer i chose because the earths atmosphere is mostly made up of different things that causes the earth to interact with human life and also interacts with what's in the atmosphere like energy oxygen carbon dioxide and all the stuff like that i hope its right.
How far will a 10N force pull a car if the work done is 20J?
A 0.41kg football that is initially at rest acquires a velocity of 35m/s when it is kicked. If the kicker's boot remains in contact with the ball for 0.08s, what is the average force of the kick?
Answer:
F = 318.88[N]
Explanation:
This problem can be solved by the principle of momentum conservation, which tells us that momentum is preserved before and after kicking the ball.
In this way, we can construct the following equation.
[tex]F*t=m*v[/tex]
where:
F = force [N]
t = time = 0.08 [s]
m = mass = 0.41 [kg]
v = velocity [m/s]
[tex]F*0.045=0.41*35\\F=318.88[N][/tex]
what is the electrical potential at the surface of gold nucleus? The radius of a gold atom is 6.6*10
Complete question is;
What is the electrical potential at the surface of gold nucleus? The radius of a gold atom is 6.6 × 10^(-5) m and atomic number z = 79.
Answer:
172.36 × 10^(-5) V
Explanation:
We are given;
Radius; r = 6.6 × 10^(-5) m
Atomic number; Z = 79
Formula for Electric potential here is;
V = kZe/r
Where;
e is charge on proton = 1.6 × 10^(-19) C
k has a constant value of 9 × 10^(9) N⋅m²/C²,
Thus;
V = (79 × 1.6 × 10^(-19) × 9 × 10^(9))/(6.6 × 10^(-5))
V = 172.36 × 10^(-5) V
A 1,000 kg truck initially had a velocity of 9 m/s. A force acts on it for a duration of time. After that force, the truck now has a velocity of 17 m/s. What is the impulse that the truck experienced?
Answer:
8000Ns
Explanation:
Given parameters:
Mass of the truck = 1000kg
Initial velocity = 9m/s
Final velocity = 17m/s
Unknown:
Impulse = ?
Solution:
The impulse experienced by the truck is the the change in momentum of the body.
Impulse = Ft
Momentum = m(v - u)
Ft = m( v - u )
F is the force
t is the time
m is the mass
v is the final velocity
u is the initial velocity
Impulse = 1000(17 - 9) = 8000Ns
what causes sound to have low pitch
A.Sound Wave with high frequency.
B.sound wave with low frequency.
C.sound wave with large amplitude
D.sound wave with small amplitude
How can the relationship between atomic number and the number of protons be described?
Answer:
It's the number of protons in the nucleus of the atom
A different bullet has a mass of 0.09 kg. Starting from rest, after its gun's trigger is pulled, a constant force acts on the bullet for the next 0.025 seconds until the bullet leaves the barrel of the gun with a speed of 1,346 m/s.
What force acts on this bullet?
The force acts on this bullet : 4.8456 N
Further explanationGiven
m=0.09 kg
Δt=0.025 s
vo=0(from rest)
vt=1.346 m/s
Required
Force
Solution
Impulse is a change in momentum
I=ΔP
F.Δt=m(vt-vo)
Input the value
F x 0.025 = 0.09(1.346-0)
F=4.8456 N
A water balloon is dropped off the top of a building and bursts when it hits
the ground 6 seconds later. What is the height of the building?
Answer:
The building is 176.4 meters high.
Explanation:
We use the formula for kinematics of an accelerated object (in this case acceleration of gravity):
Distance travelled = 1/2 g t^2
Distance travelled = 1/2 9.8 (6)^2 = 176.4 meters
1. Calculate the momentum of a 1.0 kg object moving with a velocity of +20 m/s.
2. What is the velocity of an object that has a momentum of -30 kg m/s and a mass of 3.0 kg?
3. Two objects have equal momentum but one has four times the mass of the other. What is the relationship between
their velocities?
4. Which answer below shows the correct units for momentum?
A. kg m/s
B. kg m/s?
C. kg m/s
D. kg s/m
5. Two bowling balls each have a mass of 4.0 kg
The red Bar is moving east 2.0 m/s. The blue ball is moving west at 1.0 m/s. Calculate the total momentum of the system.
Answer:
1)1*20=20
2)-30/3=- -10
3)velocity of the object 1=v1=4*V2
4) kg m/ s
5) momentum of the system= 12 kg m/ s
You throw a baseball a distance of 20 meters. Is it work or not work?
A 1.5kg object moving with a speed of 2.5m/s strikes a wall and the ball rebounds with a speed of 1.5m/s. The ball is in contact with the wall for 0.045s. What is the magnitude of the average force exerted on the ball by the wall?
Answer:
F = 133.33[N]
Explanation:
This problem can be solved by the principle of momentum conservation, which tells us that momentum is preserved before and after the bounce of the ball on the wall.
In such a way that the movement towards the wall we will take it with a positive sign, and the force of the rebound to the left as negative. The movement to the left will be taken as a negative sign.
[tex]m_{1}*v_{1}-F*t=-m_{1}*v_{2}[/tex]
where:
m₁ = mass of the object = 1.5 [kg]
v₁ = velocity of the ball before hitting the wall = 2.5 [m/s]
F = average force [N]
t = time contact = 0.045 [s]
v₂ = velocity of the ball after hitting the wall = 1.5 [m/s]
Now replacing:
[tex](1.5*2.5)-F*0.045=-(1.5*1.5)\\3.75+2.25=F*0.045\\F=6/0.045\\F=133.33[N][/tex]
A woman holds a frozen smoothie in her hand on a warm
day.
Which photo shows the direction of thermal energy transfer?
O A.↕️
B
C ⬆️
D⬇️
Answer:
C
Explanation:
The thermal energy from her hand will go up into the smoothie.
Answer:
C bois
Explanation:
Essential Questions: What does the particle theory tell us about the nature of matter? How does
each state of matter behave?
sowwie :( i need points
Explanation:
PLEASE ANSWER QUESTION 7!!!! PLEASE
Answer:
Explanation:
The force of gravity depends directly upon the masses of the two objects, and inversely on the square of the distance between them. This means that the force of gravity increases with mass, but decreases with increasing distance between objects
so a option is correct
1. A low frequency will have a wavelength?
Answer:
There are many kinds of waves all around us. There are waves in the ocean and in lakes. Did you also know that there are also waves in the air? Sound travels through the air in waves and light is made up of waves of electromagnetic energy.
The wavelength of a wave describes how long the wave is. The distance from the "crest" (top) of one wave to the crest of the next wave is the wavelength. Alternately, we can measure from the "trough" (bottom) of one wave to the trough of the next wave and get the same value for the wavelength.
The frequency of a wave is inversely proportional to its wavelength. That means that waves with a high frequency have a short wavelength, while waves with a low frequency have a longer wavelength.
Light waves have very, very short wavelengths. Red light waves have wavelengths around 700 nanometers (nm), while blue and purple light have even shorter waves with wavelengths around 400 or 500 nm. Some radio waves, another type of electromagnetic radiation, have much longer waves than light, with wavelengths ranging from millimeters to kilometers.
Sound waves traveling through air have wavelengths from millimeters to meters. Low-pitch bass notes that humans can barely hear have huge wavelengths around 17 meters and frequencies around 20 hertz (Hz). Extremely high-pitched sounds that are on the other edge of the range that humans can hear have smaller wavelengths around 17 mm and frequencies around 20 kHz (kilohertz, or thousands of Hertz).
Explanation:
Explanation:
Hope This Helped U
Brqinliest
(BRAINLIEST)
Which is an example of the force of attraction between two objects that have mass?
Magnetism
Gravity
Solar energy
Electricity
(BRAINLIEST)
Answer:
Gravity
because it's factorised by mass of a body.
For other forces, they deal with charges of negligible mass and weights
Answer:
Gravity
Explanation:
A boat moves through the water of a river at 8 m/s relative to the water, regardless of the boat's direction. If the water in theriver is flowing at 1.9 m/s, how long does it take the boat to makea round trip consisting of a 260 m displacement downstream followedby a 260 m
Answer:
68.88 m/s
Explanation:
downstream speed = 8+1.9=9.9 m/s
upstream speed = 8-1.9= 6.1 m/s
Therefore, total time taken would be 260/9.9+260/6.1 = 26.26+42.62 =
68.88 m/s
A 4 kg bowling bowl is sitting on a table 1 meter off the ground. How much potential energy does it have?
Answer:
[tex]\huge\boxed{\sf P.E. = 39.2\ Joules}[/tex]
Explanation:
Given Data:
Mass = m = 4 kg
Acceleration due to gravity = g = 9.8 m/s²
Height = h = 1 m
Required:
Potential Energy = P.E. = ?
Formula:
P.E. = mgh
Solution:
P.E. = (4)(9.8)(1)
P.E. = 39.2 Joules
[tex]\rule[225]{225}{2}[/tex]
Hope this helped!
~AH18072 benefits of yoga with explanation
Does a basketball, baseball, tennis ball, or marble MOST LIKELY have the smallest volume?
Answer: tennis ball
Explanation:
A boy walked 4m east then 3m south find the displacement
Answer:
5m
Explanation:
[tex]4^{2}+3^{2}=5^{2}\\5^{2}=25[/tex]
Use the Pythagorean theorem to calculate the long edge of the triangle, which would be his displacement.
A woman does 236 J of work
dragging her trash can 24.4 m to
the curb, using a force of 18.9 N.
At what angle was her force
directed?
Answer:
workdone = force × distance 236J = 18.9cos(o) × 24.4236/24.4 = 18.9cos(o)(0.5117)cos^-1 = (o)59.21°If a wheel rotates 5 times in 90 seconds, what is the period and frequency
Answer:
i think it should be 18
Explanation:
A 3.6kg cat is laying on a tree branch, 3 meters above the ground. What is the cat’s potential energy?
Answer:
E = 105.84 J
Explanation:
Given that,
Mass of cat, m = 3.6 kg
It is laying 3 meters above the ground.
We need to find the cat's potential energy. The formula for the potential energy of an object is given by :
E = mgh
Substituting all the values,
E = 3.6 kg × 9.8 m/s²×3 m
E = 105.84 J
So, the cat's potential energy is 105.84 J.
A spotlight on the ground shines on a wall 12 m away. If a man 2 m tall walks from the spotlight toward the building at a speed of 1.1 m/s, how fast is the length of his shadow on the building decreasing when he is 4 m from the building
Answer:
[tex]\frac{dh}{dt}=-0.4125 m/s[/tex]
Explanation:
The very first thing we can do here is to draw a sketch of the situation the problem is presenting. (See attached picture)
As you may see in the picture, we can suppose the spotlight is directly located on the ground so the light of the spotlight together with the person and the wall make two similar triangles.
In this case we need to think about the dimensions of the triangle that will change over time. We will call them:
x= distance between the spotlight and the man.
h= height of the shadow.
So we can build a relation between the height and the length of each triangle:
[tex]\frac{h}{12}=\frac{2}{x}[/tex]
the distance between the spotlight and the wall is constant, so I can directly write the 12 in my equation and the height of the man is constant as well, so I can write the 2 directly into the equation.
Next, we can solve the equation for h (since we are interested in figuring out how fast the height of the shadow is decreasing) so we get:
[tex]h=\frac{24}{x}[/tex]
So next, we need to take the derivative of the equation, since the derivative of a position function will give us the velocity at which that position is changing.
First we rewrite the equation like this:
[tex]h=24x^{-1}[/tex]
and take the derivative:
[tex]dh=-24x^{-2}dx[/tex]
we can rewrite the derivative like this:
[tex]\frac{dh}{dt}=-\frac{24}{x^{2}} \frac{dx}{dt}[/tex]
where:
dh/dt is the velocity at which the height of the shadow is decreasing (that's why our equation has a negative sign in front of it).
dx/dt is the velocity at which the value of x is increasing. In other words, how fast the man is moving away from the spotlight.
So we can go ahead and substitute:
we wish to find the velocity at which the shadow's height is decreasing when the distance between the man and the building is 4m, so in this case, x=12-4=8m
[tex]\frac{dh}{dt}=-\frac{24}{8^{2}}(1.1 m/s)[/tex]
so we get:
[tex]\frac{dh}{dt}=-0.4125 m/s[/tex]
Victor covers 210 km by car at a speed of 70 km/hr. find the time taken to cover this distance.
Answer:
3 hrs
Explanation:
the distance covered by victor= 210 km
speed= 70 km/hrs
so, 70×3= 210
so the answer is 3 hrs
BTW im a small kid so don't just right away say the explanation sucks and the subject physics is not yet started in my grade.
edit: don't give me brainless answer plz.
An inductor with an inductance of .5 henrys (H) is to be connected to a 60 Hz circuit. What will the inductive reactance (X L) be
Answer:
1885.2 ohms
Explanation:
Step one:
given data
L=5H
f=60Hz
Required
The inductive reactance of the inductor
Step two:
Applying the expression
XL= 2πfL
substitute
XL=2*3.142*60*5
XL=1885.2 ohms
what is kinetic energy
Answer:
Kinetic energy is energy of motion
Explanation:
Of potential energy which is energy that is stored
A sled with a mass of 20 kg is sliding along the snow with a velocity of 5 m/s. What is the momentum of the sled?
Question 7 options:
100 kg/ms
4 kg/ms
15 kg/ms
25 kg/ms
Answer:
100kgms⁻¹
Explanation:
Given parameters:
Mass of the sled = 20kg
Velocity of the sled = 5m/s
Unknown:
Momentum of the sled = ?
Solution:
The momentum of a body is the quantity of motion such a body possesses. Due to this;
Momentum = mass x velocity
Now insert the parameters and solve;
Momentum = 20 x 5 = 100kgms⁻¹