Câu trả lời:
C. 60 m
Giải trình:
Cho rằng:
Tốc độ tại A, u = 5m / s
Tốc độ tại B, v = 15m / s
Độ dài quãng đường, AB =?
Tổng thời gian di chuyển = 6 giây
Hãy tính gia tốc, a:
a = (v - u) / t
a = (15 - 5) / 6
a = 1,667 m / s²
Từ :
v² = u² + 2aS
Trong đó, S = khoảng cách
15² = 5² + 2 (1.667 * S)
225 = 25 + 3,334S
225 - 25 = 3,334S
200 = 3,334S
S = 200 / 3,334
S = 59,98 m
S = 60 m
A student starts a stop-watch when the bob reaches to point M.He counts each time the bob changes direction and stop the watch on the tenth change in direction.The watch shows a time of 12.0 seconds.calculate the time period
Answer:
m
Explanation:
.
What is 3.75 x 10^-7?
Answer:
Explanation:
3.75 * 10^-7
=3.75 * 1/10^7
=3.75/10000000
=3/800000000
any base which has it's power negative do it's reciprocal then the power will be positive.
Thermodynamics
Sad
064105 adt
What is energy required to melt (10.0 g) mass of aluminum that
is at its melting point? Knowing that the heat of fusion of
aluminum is (380 kJ/kg.)
Answer:
E = 3.8 kJ
Explanation:
Given that,
The mass of the object, m = 10 g = 0.01 kg
The heat of fusion of aluminum is 380 kJ/kg
We need to find the energy required to melt the mass of the aluminium. It can be calculated as follows:
E = mL
So,
E = 0.01 × 380
E = 3.8 kJ
So, the energy required to melt the mass is equal 3.8 kJ.
A construction worker is carrying 40kg if he travels a distance of 50 meters how much work is being done
Answer:
Workdone = 19600 Nm
Explanation:
Given the following data;
Mass = 40 kg
Distance = 50 meters
We know that acceleration due to gravity is equal to 9.8 m/s².
To find the work done;
First of all, we would determine the force being exerted by the construction worker.
Force = mass * acceleration due to gravity
Force = 40 * 9.8
Force = 392 Newton
Next, we would determine the work done;
Workdone is given by the formula;
[tex] Workdone = force * distance[/tex]
[tex] Workdone = 392 * 50 [/tex]
Workdone = 19600 Nm
Pls answer……………………..
2nd egg experienced more impulse
Hope this helps! :)
When a table tennis ball on a thread is made to touch the vibrating prong of a tuning fork the ball swings backwards and forwards. How can this demonstration be used to explain how sound waves are made?
state the principle of quantization of charge
Answer:
Charge quantization is the principle that the charge of any object is an integer multiple of the elementary charge
Answer: Charge quantization is the principle that the charge of any object is an integer multiple of the elementary charge. Thus, an object's charge can be exactly 0 e, or exactly 1 e, −1 e, 2 e, etc., but not, say, 12 e, or −3.8 e
Explanation:
What is the energy of a photon of red light with a wavelength of 6.47 x 10-7 m ?
Answer:
3.44×10-27 joules.
Explanation:
E = h * c / λ = h * f,
E is the energy of a photon
h is the Planck constant
c is the speed of light
λ is the wavelength
I have my exam monday I need some help!
A man standing on a dock is watching the waves pass by the end of the dock. He times the passage of the waves as one crest every 2.5 s. He estimates the distance between two crests to be 2.0 m. How fast are the waves moving?
Answer:
Explanation:
If the passage of the waves is one crest every 2.5 seconds, then that is the frequency of the wave, f.
The distance between the 2 crests (or troughs) is the wavelength, λ.
We want the velocity of this wave. The equation that relates these 3 things is
[tex]f=\frac{v}{\lambda}[/tex] and filling in:
[tex]2.5=\frac{v}{2.0}[/tex] so
v = 2.5(2.0) and
v = 5.0 m/s
Does understanding Earth’s place in the universe and the relationships of different objects in the solar system help people plan for the future of our planet?
Answer:
Yes
Explanation:
If there were to be a supernova of a star or a planet/meter that was directed at earth, then we would know in advance and make a plan to stop it
A stone is thrown upward with a kinetic energy of 10J. If it goes up to a maximum height of 5 m, find the initial velocity and mass of the stone
Answer:
Explanation:
Begin by remembering that at the stone's max height, the final velocity there is 0. Being in possession of that information along with the fact that the pull of gravity due to acceleration is -9.8 m/s/s, we can use the equation
[tex]v^2=v_0^2+2a[/tex]Δx where v is the final velocity, v₀ is the initial velocity, a is the pull of gravity, and Δx is the displacement. Filling in:
[tex]0^2=v_0^2+2(-9.8)(5.0)[/tex]
0 = v₀² - 98 so
98 = v₀² and
v = 9.9 m/s Now we can put that into the KE equation.
[tex]10=\frac{1}{2}m(9.8)[/tex] and
[tex]m=\frac{2(10)}{98}[/tex] so
m = .20 kg
If the net external torque acting on the particle is zero, the it satisfies - 1st condition of equilibrium - 2nd condition of equilibrium - Both 1st & 2nd condition of equilibrium - 2nd law of motion
Answer:
a) the distances are zero, Both 1st & 2nd condition
c) the torques are equal but of the opposite sign, 2nd condition of equilibrium
Explanation:
The equilibrium conditions are
1 translational
∑ F = 0
2 rotational
∑ τ = Σ (F_i x r_i) = 0
They tell us that external torque is zero.
Therefore we have two various possibilities
a) the distances are zero, in this case we have a pure translation movement
for this situation the two equilibrium relations are fulfilled
b) the forces are zero, there is no movement
It does not make sense to use the equilibrium relations since there are no forces
c) the torques are equal but of the opposite sign, the forces are on the opposite side of the body.
In this case the 2 equilibrium relation is fulfilled, but not the first one that the force has the same direction
10. Discrimination refers to behaviors that
a allow us to tell one ethnic group from another.
b occur when members of a racial group threaten an individual's security.
c prevent individuals from doing things they should be able to do.
d are directed toward a particular group.
Answer:
d)
Explanation:
the only one that makes sense
If a serve hits the net, what happens?
• Re-do
• Dead Ball
• Other teams point
• Play the ball
Answer:
Depends: Is it tennis or volleyball?
Explanation:
If it's volleyball, it's C, the other teams point.
If it's tennis, it's A, you get a re-do.
help me please
only if you really know
Assume R is measured in meters (m) and M in kilograms (kg). Then
R ² / (GM) = [m]² / ([N•m²/kg²] [kg]) = m•kg / N = m•kg / (kg•m/s²) = s²
so t ² is indeed proportional to R ²/(GM).
A student connects a small solar panel to a 40 a resistor to make a simple circuit. The solar panel produces a voltage of 2 0.
a Calculate the current in the student's circuit.
Ohm's law states that :
[tex]v = ir[/tex]the terms used are :
[tex]r = resistance[/tex][tex]v = potential \: \: difference[/tex][tex]i = current[/tex]let's solve for electric current :
[tex]2 = i \times 40[/tex][tex]i = \dfrac{2}{40} [/tex][tex]i = 0.05 \: A[/tex][tex]i = 50 \: mA[/tex][tex]\mathfrak{good\: \: luck \: \: for \: \: your \: \: assignment}[/tex]
A ball is tossed vertically upward. When it reaches its highest point (before falling back downward) Group of answer choices the velocity is zero, the acceleration is directed downward, and the force of gravity acting on the ball is directed downward. the velocity is zero, the acceleration is zero, and the force of gravity acting on the ball is zero. the velocity is zero, the acceleration is zero, and the force of gravity acting on the ball is directed downward. the velocity and acceleration reverse direction, but the force of gravity on the ball remains downward. the velocity, acceleration, and the force of gravity on the ball all reverse direction.
Answer:
the velocity is zero, the acceleration is directed downward, and the force of gravity acting on the ball is directed downward
Explanation:
Is this exercise in kinematics
v = v₀ - g t
where g is the acceleration of the ball, which is created by the attraction of the ball to the Earth.
At the highest point
velocity must be zero.
The acceleration depends on the Earth therefore it is constant at this point and with a downward direction.
The force of the earth on the ball is towards the center of the Earth, that is, down
all other alternatives are wrong
when a car drives in a circle there must be ?
no net force axting on it
Answer:
I think none of above
Explanation:
hioe it's right answer
8. A satellite weighs 200 newtons on the surface of
Earth. What is its weight at a distance of one Earth
radius above the surface of Earth?
1) 800 N
3) 100 N
2) 400 N
4) 50 N
The weight of the satellite at a distance of one Earth radius above the surface of Earth is 40 N.
The given parameters:
Weight of the satellite, F = 200 NOne Earth radius above the surface of Earth = 2RThe gravitational force on the satellite is calculated by applying Newton's law of universal gravitation is calculated as;
[tex]F = \frac{Gm_1m_2}{R^2} \\\\F_1 R_1^2 = F_2R_2^2\\\\F_2 = \frac{F_1 R_1^2 }{R_2^2} \\\\F_2 =\frac{200 \times R_1^2}{(2R_1)^2} \\\\F_2 = \frac{200 \times R_1^2 }{4R_1} \\\\F_2 = 40 \ N[/tex]
Thus, the weight of the satellite at a distance of one Earth radius above the surface of Earth is 40 N.
Learn more about Newton's law of universal gravitation here: https://brainly.com/question/9373839
A 4 mm object is observed by a magnifying lens as 1.25 cm. Calculate the ratio do/di.
Answer:
dₒ/dᵢ = 0.32
Explanation:
From the question given above, the following data were obtained:
Object height (Hₒ) = 4 mm
Image height (Hᵢ) = 1.25 cm
Ratio of object distance (dₒ) to image distance (dᵢ) [dₒ/dᵢ] =?
Next, we shall convert 4 mm to cm. This can be obtained as follow:
10 mm = 1 cm
Therefore,
4 mm = 4 mm × 1 cm / 10 mm
4 mm = 0.4 cm
Next, we shall determine the magnification of the lens. This can be obtained as follow:
Object height (Hₒ) = 4 mm
Image height (Hᵢ) = 1.25 cm
Magnification (M ) =?
M = Hᵢ/Hₒ
M = 1.25 / 0.4
M = 3.125
Finally, we shall determine the ratio of object distance (dₒ) to image distance (dᵢ). This can be obtained as follow:
Magnification (M) = 3.125
Ratio of object distance (dₒ) to image distance (dᵢ) [dₒ/dᵢ] =?
Magnification (M) = image distance (dᵢ) / object distance (dₒ)
M = dᵢ/dₒ
Invert
1/M = dₒ/dᵢ
1/3.125 = dₒ/dᵢ
dₒ/dᵢ = 0.32
Therefore, the ratio of object distance (dₒ) to image distance (dᵢ) [dₒ/dᵢ] is 0.32
convert 4 kilograms into grams with process
The length of second hand of clock is 14cm, an ant sits on the top of second hand. find the following
i) speed of ant
ii) distance covered by ant in 150 seconds
iii) displacement in 150 seconds
Answer:
i) v = 1.47 cm/s
ii) distance = 219.8 cm
iii) displacement = 28cm
Explanation:
Remember that:
The motion of the tip of the second hand is a circular motion.
For something that rotates with an angular frequency ω, and a radius R, the velocity is given by:
v = ω*R.
i) We know that the second hand of a clock does a complete rotation each 60 seconds.
Then the period is:
T = 60s
And the frequency is the inverse of the period, so:
f = 1/T
f = (1/60s)
And the angular frequency is 2*pi times the normal frequency, thus:
ω = 2*pi*f
ω = 2*pi*(1/60s) = (2*pi/60s)
And the radius will be 14 cm, the velocity of the ant is:
v = (2*pi/60s)*14cm
if we replace pi by 3.14 we get:
v = (2*3.14/60s)*14cm = 1.47 cm/s
ii) The distance covered by the ant in 150 seconds:
Remember that the period of the clock is T = 60s
so in 150 seconds we have:
150s/60s = 2.5 revolutions.
Then the total distance covered is 2.5 times the perimeter of a circle of radius R = 14cm, this is:
distance = (2.5)*2*pi*14cm
= (2.5)*2*3.14*14cm = 219.8 cm
iii) We want to know the displacement, this is, the difference between the final position and the initial position.
In 150 seconds, the ant does 2.5 revolutions.
So the ant will end in the opposite side of the circle where she started (if the ant started when the second hand was at the "3", then the final position is when the second hand is at the "9").
So the displacement will be equal to twice the radius, or the diameter of the circle.
if the radius is 14cm, the diameter is:
2*14cm = 28cm
the displacement is 28cm
What is resistance? Difference between resistance and resistivity.
Answer:
Resistance is a measure of the opposition to current flow in an electrical circuit.All materials resist current flow to some degree. They fall into one of two broad categories: Conductors: Materials that offer very little resistance where electrons can move easily.
b) The relation of the gravitational constant is given as G = If the d mm between two masses is increased, will the value of G increase, decrease or re constant? Write in short.
Answer:
G is universally constant
Explanation:
The Gravitational constant G, is a proportionality constant for all objects in the universe with a value of ; G = 6.67*10^-11 m³kg^-1s^-2.
According to the the Newton's Law of Universal Gravitation ; Every object in the universe attracts one another with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distances between them.
F α m1m2 α 1/r²
F α m1m2/r²
F = Gm1m2 / r²
m1 and m2 are the masses ; r = distance between them
G = Gravitational constant.
What is the position and kind of image produced by the lens below?
Complete the ray diagram to support your answer.
what is the mystery behind black hole
Well since the gravitational pull is so strong, nothing can escape from it which means we haven't been able to get close enough to really know everything about them. There's no way of knowing what truly goes on inside of them since there is no way out.
Answer:
A black hole is a region of spacetime where gravity is so strong that nothing—no particles or even electromagnetic radiation such as light—can escape from it. The theory of general relativity predicts that a sufficiently compact mass can deform spacetime to form a black hole.
Explanation:
10.
You are standing on a sheet of ice that covers the football stadium parking lot in Buffalo; there is
negligible friction between your feet and the ice. A friend throws you a 0.4 kg ball that is traveling
horizontally at 10 m/s. Your mass is 70 kg. If you catch the ball, with what speed do you and the ball
move afterwards?
1.02 m/s
0.06 m/s
0.02 m/s
0.12 m/s
Answer:
Explanation:
This is a classic Law of Momentum Conservation problem. For us the equation will look like this:
[tex][(m_yv_y+m_bv_b)]_b=[(m_y+m_b)v_{both}]_a[/tex] Filling in with our given info:
[tex][(70.0)(0)+(.40)(10.0)]_b=[(70.0+.40)v_{both}]_a[/tex] and
4.0 = 70.4v and
v = .06 m/s
On which planet would your weight be the most and the least?
a.Jupiter and Mercury
B.Jupiter and Neptune
c.Saturn and Neptune
D.
Saturn and Uranus
Answer: on jupiter you would weigh the most and on mars you would weigh the least
Explanation:
The frequency of a wave is the inverse of the wave's
wavelength
itude
perod
velocit
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that's according to ma observation