Answer:
-4m/s
Explanation:
use the formula
[tex]f = ma[/tex]
where f-force
m-mass
a-accleration
so
1kN=1000N
so apply
4000=1000×a
a=4m/s
(the negative is because the car was braking)
Answer:
Your answer is -4 m/s^2
Explanation:
Set Up: Let +x be the direction the car is traveling.
List the known & unknown quantities:
m = mass of the car = 1000 kg
υ = 30 m/s
Fx = –4 kN = –4000 N (negative since it is a braking force)
ax = acceleration =?
Solve: Use Newton’s second law of motion.
Fx=max
ax=Fx/m = −4000 N /1000 kg = −4000 kg·m/s^2 / 1000 kg =−4m/s^2
When a snowball turns into a puddle of
water, we know that
A. there is no change in the motion of the particles in the
puddle
B. the snowball's energy does not change; no phase change
occurs.
C. the snowball loses energy and changes from a liquid to a
solid,
D. the snowball gains energy and changes from solid to
liquid,
When a snowball turns into a puddle of water, we know that (the snow ball gains energy and changes from a solid to liquid).
This is correct due to the fact that particles of the snowball are gaining speed and so it is heating up, when the solid's temperature reaches the melting point, it will become a liquid.
Therefore, D is the correct answer.
One solution to minimize resonance with buildings is to ______ the width to span ratio.
Answer:
Increase
Explanation:
Resonance is a phenomenon which occurs when a body A in motion set another body B into motion of it own natural frequency. So for resonance to be minimize in a body is to increase the width to span ratio. So as to reduce the overall vibration which affects directly building resonance, the stiffness or trusses and girders should be increase. The increase in this aspect helps to reinforce building structure and support.
A 777-\text{ kg} kgstart text, space, k, g, end text object is accelerating to the right at 2 \text{ km}/\text{s}^22 km/s 2 2, start text, space, k, m, end text, slash, start text, s, end text, squared. What is the magnitude of the rightward net force acting on it
Answer: 14000 N
Explanation: i just did it on khan academy
on heating gases expand ______________ than solids and liquids
Answer:
On heating gases expands than solid and liquid because the molecules gets seperated and the volume increases that causes to expand.
Explanation:
Hope it is helpful
please mark me as brainliest
please
A damped mass/spring system takes 14.0 s for its amplitude of the oscillator to decrease by a factor of 9. By what factor does the energy of the mass/spring system decrease over that time?
Answer:
The correct answer is "0.246".
Explanation:
Given that the amplitude is decreased by a factor of 9, then
[tex]A \rightarrow (A-\frac{A}{9} )[/tex]
[tex]A \rightarrow \frac{8A}{9}[/tex]
As we know,
Energy will be:
⇒ [tex]E_{1}=\frac{1}{2}KA^2[/tex]
and,
⇒ [tex]E_{2}=\frac{1}{2}K(\frac{8A}{9} )^2[/tex]
[tex]=\frac{64KA^2}{162}[/tex]
⇒ [tex]\Delta E=E_1-E_2[/tex]
On putting the estimated values, we get
[tex]=\frac{1}{2}KA^2-\frac{64KA^2}{162}[/tex]
⇒ [tex]\frac{\Delta E}{E}=\frac{\frac{20}{162}KA^2}{\frac{1}{2}KA^2}[/tex]
[tex]=\frac{40}{162}[/tex]
[tex]=0.246[/tex]
Train cars are coupled together by being bumped into one another. Suppose two loaded train cars are moving toward one another, the first having a mass of 270000 kg and a velocity of 0.325 m/s in the horizontal direction, and the second having a mass of 52500 kg and a velocity of -0.12 m/s in the horizontal direction. What is their final velocity?
Answer:
0.252 m/s
Explanation:
Applying the law of conservation of momentum,
Total momentum before collision = Total momentum after collision
Note: From the question, The collision between the car and the train is an inelastic collision and as such, both move with a common velocity after collision.
mu+m'u' = V(m+m')................... Equation 1
Where m = mass of the train, u' = initial velocity of the train, m' = mass of the car, u' = initial velocity of the car, V = common velocity after collision.
make V the subject of the equation
V = (mu+m'u')/(m+m')............... Equation 2
Given: m = 270000 kg, u = 0.325 m/s, m' = 52500 kg, u' = -0.12 m/s
Substitute these values into equation 2
V = [(270000×0.325)+{52500(-0.12)}]/(270000+52500)
V = 81450/322500
V = 0.252 m/s
What happens when white light shines through a translucent, red, glass window? a) All colors of light except red are transmitted through the glass. b) Red light is transmitted through and reflected by the glass c) Red light is absorbed by the glass d) all colors except red are reflected by the glass
Answer:
b. Red light is transmitted through and reflected by the glass
Explanation:
Give me brainliest plz!
All of the wavelengths of the red light are absorbed when it passes through a translucent red glass window, but the red light is transmitted and reflected.
What happens when white light shines through red glass?Red light emerges from the other side of a white light source that has been passed through a red filter. This is so that only red light can pass through the red filter. The spectrum's other colors (wavelengths) are absorbed. Similar to this, a green filter only lets through green light.White light is colorless light that contains all the wavelengths of the visible spectrum. Only specific wavelengths of white light are filtered through transparent or translucent things.Through a colorful glass, white light shines through. Except for the color it is shining through, all light wavelengths are absorbed by the glass.Therefore, if the red light passes through a translucent, red, glass, window, all the wavelengths are absorbed but the red light is transmitted and reflected.
Therefore, the correct answer is option b) Red light is transmitted through and reflected by the glass.
To learn more about light refer to:
https://brainly.com/question/12002703
#SPJ2
During a collision with another car, the occupants of a minivan initially travelling at 4.0 m/s come to a complete stop in 0.5 s. What was the acceleration of the occupants of the minivan?
a) 8.0 m/s2
b) –8.0 m/s2
c) 2.0 m/s2
d) –2.0 m/s2
Answer: b) - 8.0 [tex]m/s^{2}[/tex]
Explanation: Acceleration is a vector indicating a rate an object's velocity changes over time:
a = [tex]\frac{v}{t}[/tex]
and its SI unit is [tex]m/s^{2}[/tex]
For the minivan to stop, it takes a period of 0.5s:
a = [tex]\frac{4.0}{0.5}[/tex]
a = 8.0 [tex]m/s^{2}[/tex]
As a vector, acceleration has magnitude (8[tex]m/s^{2}[/tex]) and direction. Since it is stopping, the minivan has a direction opposite to the other car, which means acceleration is negative. So: a = [tex]- 8.0 m/s^{2}[/tex].
Read the excerpt from "Justin Lebo.” When he got it home, he wheeled the junker into the garage and showed it proudly to his father. "Will you help me fix it up?" he asked. Justin's hobby was bike racing, a passion the two of them shared. Their garage barely had room for the car anymore. It was more like a bike shop. Tires and frames hung from hooks on the ceiling, and bike wrenches dangled from the walls. Based on the details in this excerpt, which word best describes the garage? inviting dangerous cluttered sparse
Answer:
cluttered
Explanation:
The correct word to describe the garage would be cluttered.
A place is said to be cluttered when it is filled with an untidy collection of material things. In this case, the garage is filled with materials such as bike wrenches, tires, frames, etc.
Inviting can also mean tempting, attractive, etc, and has no relevance to the condition of the garage as described in the excerpt.
Dangerous can also mean harmful, and not the right word to describe the garage.
Sparse can also mean scanty, scattered, and would be the opposite of the condition of the garage.
Correct answer: cluttered
Answer:
c. cluttered
Explanation:
What is an electron?
A. A negative particle inside the nucleus
B. A negative particle outside the nucleus
C. A positive particle inside the nucleus
D. A particle inside the nucleus that has no charge
Answer:
B. A negative particle outside the nucleus
Explanation:
Electrons are very small particles orbiting outside of the nucleus of an atom. They carry negative charges.
The nucleus only contains protons and neutrons. Protons are positive, and neutrons have no charge (i.e. neutral)
A refrigerator recieves 240 V of electricity. If it use 32 A of current, what is the resistance of the refrigerator?
Answer:
7.5 Ω
Explanation:
Voltage = Current x Resistance
(V = IR)
240 = 32 R
R = 240 / 32
= 7.5 Ω
(b) 360 days into seconds.
Sec
(c)
(d) A body has weight 60
0 N on the surface of the mars then what is its mass on the
[Ans: 157.89 kg)
What is weight of a body of mass 100 kg on the surface of the moon? [Ans: 166N]
Explanation:
(b) We know that,
1 day = 24 hours
1 hour = 3600 s
So, we found that, 1 day = 86400 s
We need to find the 360 days into seconds. So,
1 day = 86400 s
360 days = 86400×360
360 days = 31104000 seconds
(d) Weight of a body, W = 600 N
Acceleration due to gravity on mars is 3.7 m/s²
Weight, W = mg
m is mass of body
[tex]m=\dfrac{W}{g}\\\\m=\dfrac{600}{3.7}\\\\m=162.16\ kg[/tex]
(e) Mass of body, m = 100 kg
Acceleration due to gravity on the moon, 1.6 m/s²
Weight, W = 100 × 1.6
W = 160 N
In an oscillating LC circuit, the maximum charge on the capacitor is qm. Determine the charge on the capacitor, q, and the current through the inductor, I, when energy is shared equally between the electric and magnetic fields. Express your answers in terms of qm, L, and C.
Answer:
a. q = qm/√2 b. qm/√(2LC)
Explanation:
a. Charge on the capacitor
Let U₁ = energy in inductor and U₂ = energy in capacitor and U = total energy in circuit.
So, U₁ + U₂ = U.
Since the energy is shared equally between the capacitor and inductor, U₁= U₂,so
2U₂ = U
and U₂ = U/2
Now U₂ = q²/2C where q is the charge on the capacitor with capacitance C and
U = (qm)²/2C where qm is the maximum charge on the capacitor.
Since U₂ = U/2,
Substituting the values for U₂ and U, we have
q²/2C = [(qm)²/2C]/2
q² = (qm)²/2
taking square-root of both sides, we have
q = qm/√2
b. The current in the inductor
Since the energy in the capacitor equals the energy in the inductor,
1/2LI² = 1/2q²/C where L is the inductance of the inductor and I the current through it.
I² = q²/LC
taking square-root of both sides, we have
I = q/√LC
substituting the value of q from above, we have
I = qm/√2 ÷ √LC
I = qm/√(2LC)
(c) An object of mass 100 kg is accelerated uniformly from a velocity of 15m/s to 20 m/s in 10 s.
Calculate the initial and final momentum of the object.
Also, find the magnitude of the force exerted on the object.
Explanation:
momentum = mass x velocity
initial momentum = 100 x 15 = 1500kgm/s
after momentum = 100 x 20 = 2000kgm/s
a =(v-u)/t
a = (20-15)/10
a = 5/10
a = 0.5m/s²
f = ma
f = 100 x 0.5
f = 50N
You and a friend are on a swing set and her swing is slightly longer than yours. If you both start swinging at the same time, from the same height, where will she be after you have completed one complete swing back and forth?
a. She will still be at the same height as you.
b. She will be slightly higher than you.
c. She will be slightly lower than you but moving downward away from you.
d. She will be slightly lower than you but moving upward toward you.
Answer:
d. She will be slightly lower than you but moving upward toward you.
Explanation:
Since your swing is slightly shorter than your friend's swing, then you will have more angular speed than your friend. Angular speed increases with a decrease in radius. The closer the body is to the center, the faster the body swings. By the time you would have completed one complete swing back and forth, your friend will just be moving towards you, and she will be slightly lower than you but moving upwards towards you. This principle is the same reason gymnasts pull their limbs closer to their body when they need to swing faster.
Write the equation for simple harmonic motion (x-t),(v-t), and find v at t=2s and t=3s if the object is initially at the right extreme of origin and moving in the negative x-direction. (A=2cm, T=8s)
Answer:
Explanation:
T = 8 s
angular frequency ω = 2π / T
= 2 π / 8
= π / 4
x ( t ) = A ( sinωt + π / 2 ) because initial phase difference is π / 2
= A cos ωt
= A cos π t / 4
v = Aω sinωt
= 2 x π / 4 sinωt
= .5 π sinπt / 4
when t = 2
v = .5 π sinπ x 2 / 4
= .5 π x 1
= 1.57 cm /s
At t = 3 s
v = .5 π sin π x 3 / 4
= .5 π sin 135°
= .5 π / √ 2
= 1.11 cm /s
A carpenter measured the lengeth of a small piece of timber as 24.6cm .Calculate the relative error in the measurement if the true length is 24.5cm
ANSWER:
0.4081%
Explanation:
Difference=24.6-24.5=0.1
Relative error = 0.1/24.5*100=0.4081%
Relative error is equal to the = difference between both the values/The true value *100
Maximum voltage produced in an AC generator completing 60 cycles in 30 sec is 250V. (a) What is period of armature? (b) How many cycles are completed in T/2 sec? (c) What is the maximum emf produced when the armature completes 180 0 rotation?
Answer:
a. 2 Hz b. 0.5 cycles c . 0 V
Explanation:
a. What is period of armature?
Since it takes the armature 30 seconds to complete 60 cycles, and frequency f = number of cycles/ time = 60 cycles/ 30 s = 2 cycles/ s = 2 Hz
b. How many cycles are completed in T/2 sec?
The period, T = 1/f = 1/2 Hz = 0.5 s.
So, it takes 0.5 s to complete 1 cycles. At t = T/2 = 0.5/2 = 0.25 s,
Since it takes 0.5 s to complete 1 cycle, then the number of cycles it completes in 0.25 s is 0.25/0.5 = 0.5 cycles.
c. What is the maximum emf produced when the armature completes 180° rotation?
Since the emf E = E₀sinθ and when θ = 180°, sinθ = sin180° = 0
E = E₀ × 0 = 0
E = 0
So, at 180° rotation, the maximum emf produced is 0 V.
# A cheetah can start from rest and attain the velocity 72km/h in 2 seconds. Calculate the acceleration of cheetah
Answer:
[tex]10 \: [/tex] m/s ^2Explanation:
Solution,
When a certain object comes in motion from rest, in the case, initial velocity = 0 m/s
Initial velocity ( u ) = 0 m/s
Final velocity ( v ) = 72 km/h ( Given)
We have to convert 72 km /h in m/s
[tex]72 \: km \: per \: hour[/tex]
[tex] = 72 \times \frac{1000}{60 \times 60} [/tex]
[tex] = 20 [/tex] m/s
Final velocity ( v ) = 20 m/s
Time taken ( t ) = 2 seconds
Acceleration (a) = ?
Now,
we have,
[tex]a = \frac{v - u}{t} [/tex]
[tex]a = \frac{20 - 0}{2} [/tex]
[tex]a = \frac{20}{2} [/tex]
[tex]a = 10 [/tex] m/s ^2
Hope this helps...
Good luck on your assignment..
What are the signs of the velocity, force, and acceleration (components) afterthe cart is released and is moving qway from the motion sensor? (The positive xdirection is toward the motion sensor, to the right.
Answer:
car is moving away its direction is negative.
the speed must also be negative.
speed this distance decreases the acceleration is negative and if the speed is increasing the acceleration is positive.
Explanation:
In the exercise they indicate that the direction to the motion sensor is positive, as they indicate that the car is moving away its direction is negative.
The speed of the car is
v = (x₂-x₁) / t
As the positions are negative, and the car moves away the speed must also be negative.
The analysis for acceleration must be very careful if the speed this distance decreases the acceleration is negative and if the speed is increasing the acceleration is positive.
help me its emergency I need a correct answer please if you don't know then please dont guess
Answer:
True.
Explanation:
Total internal reflection is bound to occur when light travels from dense medium to less dense.
From the table given in the question above, we obtained:
Refractive Index of Crown glass = 1.52
Refractive Index of Asphalt = 1.635
From the above, Crown glass has a lower refractive index when compared to Asphalt. This means that Crown glass is less dense than Asphalt.
Therefore, total internal reflection will not occur when light travels from Crown glass to Asphalt because Crown glass is less dense than Asphalt.
A wave travels at 295 m/s and has a wavelength of 2.50 m. What is the frequency of the wave?
O 118 Hz
O 292 Hz
O297 Hz
O 738 Hz
Answer:
[tex]118\; \rm Hz[/tex].
Explanation:
The frequency [tex]f[/tex] of a wave is equal to the number of wave cycles that go through a point on its path in unit time (where "unit time" is typically equal to one second.)
The wave in this question travels at a speed of [tex]v= 295\; \rm m\cdot s^{-1}[/tex]. In other words, the wave would have traveled [tex]295\; \rm m[/tex] in each second. Consider a point on the path of this wave. If a peak was initially at that point, in one second that peak would be
How many wave cycles can fit into that [tex]295\; \rm m[/tex]? The wavelength of this wave[tex]\lambda = 2.50\; \rm m[/tex] gives the length of one wave cycle. Therefore:
[tex]\displaystyle \frac{295\;\rm m}{2.50\; \rm m} = 118[/tex].
That is: there are [tex]118[/tex] wave cycles in [tex]295\; \rm m[/tex] of this wave.
On the other hand, Because that [tex]295\; \rm m[/tex] of this wave goes through that point in each second, that [tex]118[/tex] wave cycles will go through that point in the same amount of time. Hence, the frequency of this wave would be
Because one wave cycle per second is equivalent to one Hertz, the frequency of this wave can be written as:
[tex]f = 118\; \rm s^{-1} = 118\; \rm Hz[/tex].
The calculations above can be expressed with the formula:
[tex]\displaystyle f = \frac{v}{\lambda}[/tex],
where
[tex]v[/tex] represents the speed of this wave, and [tex]\lambda[/tex] represents the wavelength of this wave.Answer:
118
Explanation:
b. i. In a hydraulic press, a force of 200N is applied to master piston of area 25cm. If
the press is designed to produce a force of 5000N, determine the area of the slave
piston.
(4marks)
Answer:
625 cm²
Explanation:
The pressure is the same on both pistons.
F/A = F/A
200 N / 25 cm² = 5000 N / A
A = 625 cm²
On a 100km track , a train travels the first 30km with a speed of 30km/h . How fast the train travel the next 70 km if the average speed for the entire journey is 40km/h?
Answer:
v = 46.67 km/h
Explanation:
We will use the following formula throughout this numerical:
s = vt
where,
s = distance covered
v = speed
t = time taken
FOR FIRST 30 km:
s = 30 km
v = 30 km/h
t = t₃₀ = ?
Therefore,
30 km = (30 km/h)(t₃₀)
t₃₀ = (30 km)/(30 km/h)
t₃₀ = 1 h
FOR TOTAL 100 km:
s = 100 km
v = 40 km/h (Average Speed)
t = total time = ?
Therefore,
100 km = (40 km/h)(t)
t = (100 km)/(40 km/h)
t = 2.5 h
FOR LAST 70 km:
s = 70 km
t₇₀ = t - t₃₀ = 2.5 h - 1 h = 1.5 h
v = v₇₀ = ?
Therefore,
70 km = v(1.5 h)
v = 70 km/1.5 h
v = 46.67 km/h
Somebody help!?
13. The graph below represents the speed of a car vs. time. Circle the letter(s) with the lowest acceleration.
What is the acceleration? How do you know?
Answer:
acceleration is the rate of change of the velocity of an object with respect to time. Accelerations are vector quantities. The orientation of an object's acceleration is given by the orientation of the net force acting on that object.
Explanation:
Calculating acceleration involves dividing velocity by time — or in terms of SI units, dividing the meter per second [m/s] by the second [s]. Dividing distance by time twice is the same as dividing distance by the square of time. Thus the SI unit of acceleration is the meter per second squared .
explain translatory motion and give examples of various types of translatory motion
Answer:
Translatory Motion:
The motion of a body along a line is called Translatory Motion. The line may be straight or curved. There are three types:
1) Linear Motion:
Straight line motion of a body is called Linear Motion.
E.g. Movement of a car on a straight road.
2) Circular Motion:
Motion of a body along a circle is called circular motion.
E.g. Movement of a toy train along its circular track.
3) Random Motion:
The irregular motion of a body is called random motion.
E.g. Movement of a bee.
.......Hope it helps :)........
I need help asap please please
a light ray strikes at a plane mirror at an angle of incident of 35 degree what would the angle of reflection be explain???
laws of reflection
I = r
angle of incident = angle of reflection
35 = 35
correct answer will be marrk as braineast answer
Answer:
d) harvesting and threshing both.
Explanation:
Hope it helps you...
9) Of all the types of light the Sun gives off, it emits the greatest amount of light at visible wavelengths of light. If the Sun were to cool off dramatically and as a result start giving off mainly light at wavelengths longer than visible light, how would the frequency, energy, and speed of this light given off by the Sun also be different? Explain your reasoning.
Answer:
* most of the emission would be in the infrared part, the visible radiation would be very small.
*total intensity of the semition decreases that the intensity depends on the fourth power of the temperature
Explanation:
The radiation emitted by the Sun is approximately the radiation of a black body, if the Sun were to cool, the maximum emission wavelength changes
λ T = 2,898 10⁻³
λ = 2,898 10⁻³ / T
if the temperature decreases the maximum wavelength the greater values are moved, that is to say towards the infrared. Therefore the emission curve also moves, in this case most of the emission would be in the infrared part, the visible radiation would be very small.
Furthermore, the total intensity of the semition decreases that the intensity depends on the fourth power of the temperature according to Stefan's law
P = σ A eT⁴
How many excess electrons must be distributed uniformly within the volume of an isolated plastic sphere 22.0 cmcm in diameter to produce an electric field of 1340 N/CN/C just outside the surface of the sphere?
Answer:
1.125x10^-10 electrons
Explanation:
Pls see attached file