a) A car accelerates uniformly at 3.7 m s⁻² as it passes a stationary road train. The initial speed of the car is 30 m s⁻¹, and it reaches the speed limit of 130 km h⁻¹ as it passes the front of the cab. Calculate the length of the road train. Give your answer to 3 significant figures. include units in your answer.
b) The braking distance of a road train travelling at 15 m s⁻¹ is 70 m. Assuming that the same deceleration is applied at all speeds, calculate the braking distance of a road train travelling at 25 m s⁻¹
(a) The length of the train is 54.6 m
(b) The braking distance of the road train is 194.44 m
The given parameters:
acceleration of the car, a = 3.7 m/s²
initial velocity of the car, u = 30 m/s
final velocity of the car, v = 130 km/h = 36.11 m/s
To find:
the length of the trainThe length of the train is the distance travelled by the car
The distance traveled by the car is calculated as:
[tex]v^2 = u^2 + 2as\\\\2as = v^2 - u^2\\\\s = \frac{ v^2 - u^2}{2a} \\\\where;\\\\s \ is \ the \ distance \ travelled \ by \ the \ car\\\\s = \frac{(36.11)^2 - (30)^2}{2\times 3.7} \\\\s = 54.585 \ m\\\\s \approx 54.6 \ m[/tex]
Thus, the length of the train is 54.6 m
(b) The braking distance of a road train travelling at 25 m s⁻¹
[tex]a = \frac{v_1^2}{2s_1} = \frac{v_2^2}{2s_2} \\\\Given;\\\\s_1 = 70 \ m\\\\v_1 = 15 \ m/s\\\\v_2 = 25 \ m/s\\\\s_2 = ?\\\\2s_2v_1^2 = 2s_1v_2^2\\\\s_2 = \frac{ 2s_1v_2^2}{2v_1^2} \\\\s_2 = \frac{s_1v_2^2}{v_1^2} \\\\s_2 = \frac{70\times 25^2}{15^2} \\\\s_2 = 194.44 \ m[/tex]
Thus, the braking distance of the road train is 194.44 m
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Explanation of the Lunar eclipse
● Provide details such as rotation and axis.
● For lunar and solar eclipse describe partial eclipse
and total eclipse. For seasons describe all four seasons.
● Identify the relative position of the sun and earth in each case.
● Use a cause and effect to show how the chosen phenomena
occurs.
A lunar eclipse occurs when the Moon moves into the Earth's shadow. This can occur only when the Sun, Earth, and Moon are exactly or very closely aligned (in syzygy) with Earth between the other two, and only on the night of a full moon.
Why are there only two elements in the first period of the periodic table?(1 point)
because the first two elements both start with H and are grouped together
because the next elements have other things in common and they need to be arranged together
because each row increases in atomic mass by a specific number, so anything over five is in the second row
because only two electrons can fit in the first orbit around the nucleus, and each period on the table is organized by number of orbits
Answer:
because only two electrons can fit in the first orbit around the nucleus, and each period on the table is organized by number of orbits
There are only two elements in the first period of the periodic table (statement 4) because only two electrons can fit in the first orbit around the nucleus, and each period on the table is organized by the number of orbits
A period is defined as an interval required for a cycle to repeat itself.
A period is a horizontal row of the periodic table. Seven periods in the periodic table, with each one beginning from the far left to right.Periods may contain as few as two elements and as many as thirty-two elements. A new period starts when a new number of orbit or principal energy levels begins filling with electrons.Period 1 has only two elements (hydrogen and helium) as they have electrons in only the 1st energy level or first orbit and each period on the table is organized by the number of orbits or level of energy.
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What do you think the disadvantages of nuclear energy are nabilne fa
Answer:
1 . Environmental impact. Although nuclear power plants release zero carbon emissions, nuclear power still has a substantial impact on the environment, mainly through mining and water discharge. ...
2. Water intensive. ...
3.Risk of nuclear accidents. ...
4.Radioactive waste. ...
5.Non-renewable.
please follow me2. A force of 20N acts on a particle of mass 2 Kg and displaces it by 5m at an angle 30°. What is the work done? a) 40J ) b) 50 J c) 100J
Mass is not required
Force=F=20NAngle=30°Displacement=s=5m[tex]\\ \rm\longmapsto W=Fscos\Theta[/tex]
[tex]\\ \rm\longmapsto W=20(5)cos30[/tex]
[tex]\\ \rm\longmapsto W=100\times \dfrac{\sqrt{3}}{2}[/tex]
[tex]\\ \rm\longmapsto W=50\sqrt{3}J[/tex]
Answer:
[tex]we \: have \\ w = fs \cos( \alpha ) \\ f = 20n \\ m = 2kg \\ s = 5m \\ \alpha = 30 \\ \\ then \: w = 20 \times 5 \times \cos(30) \\ 100 \cos(30) \\ = 100 \frac{ \sqrt{3} }{2} \\ = 50 \sqrt{3} \\ = 86.6 \: joule\\ thank \: yo[/tex]
4. A sprinter begins from rest and accelerates at the rate of 2 m/s2 for 200 m.
a) What is the sprinter's velocity at the end of the 200 m?
b) How long does it take him to cover it?
c) What is his average velocity?
Answer:
v=28.28m/s t=14.14s average velocity =2m/s
Explanation:
Starting at rest the initial velocity is 0 substituting that in the first equation of motion v=u+atgives the final velocity but we first have to determine the time using the third equation of motion which is s=ut+1/2at^2 and then do the substitution. Average velocity is the determined by adding the initial and final velocity then divide it by 2
Every action force has an opposite and equal reaction force. Determine which of these are action/reaction pairs. Check all that apply.
Answer:
where are the questions /pairs
Explanation:
Answer:
A girl leans against a wall and the wall pushes on the girl.
A baseball hits a glove and the glove pushes on the ball.
A cat rubs up against a tree and the tree pushes against the cat
Explanation: i finished the question
all the distances from the curved surface are measured from the:
a) pole
b) centre of curvature
c) focus
d) radius of curvature
plz reply
Pole is the answer.
Actually when we measure, we use metre scale and thread. But since option doesn't have it, so Pole is the answer . Because all curved surfaces has a pole . So, we can directly measure around it.
Hope it helps you
Work out
1. A father and daughter are sitting on a seesaw that is 2 meters long. the father has a weight of 600N and the daughter has a weight of 150N. Calculate where the father has to sit to balance the child who is sitting on the other side.
the father has to sit 0.5meter away from the kid because he is a 3/4 heavier that the kid
5. A ball with momentum of 16 kg x m/s strikes a ball at rest. What is the total momentum of both balls after the collision? a. -16kg x m/s b. -8 kg x m/s c. 8 kg x m/s d. 16 kg x m/s? help please
Answer:
D. 16 Kgm/s
Explanation:
Let the momentum of the two balls be A and B respectively.
Momentum A = 16 kgm/s
Momentum B = 0 kgm/s (since the ball is at rest).
Total momentum = A + B
Total momentum = 16 + 0
Total momentum = 16 Kgm/s
Momentum can be defined as the multiplication (product) of the mass possessed by an object and its velocity. Momentum is considered to be a vector quantity because it has both magnitude and direction.
Mathematically, momentum is given by the formula;
Momentum = mass * velocity
What is environment
Answer:
environment is the situation of the place
Explanation:
i think helping you... have a great day:)
true or false
the bounciness of a ball changes with temperature
true
false
Answer:
False
Explanation:
This depends on how much air is in the ball, I think
if brittany is investigating how fast brian will react to three different sounds , what is the dependent variable in the experiment
Answer:
Dependent variable- how fast is the time that Brian will react.Explanation:
Dependent variable - a variable that you can not manipulate and the one that is being observe.[tex]\tt{ \green{P} \orange{s} \red{y} \blue{x} \pink{c} \purple{h} \green{i} e}[/tex]
A wombat runs south in a straight line with an average velocity of 5 m/s for 4
minutes and then with an average velocity of 4 m/s for 3 minutes in the same
direction.
What is the wombats total displacement?
What is the average velocity during that time?
We have that
The wombats total displacement is
[tex]d_t=2100m[/tex]
The average velocity during that time is
[tex]v_{avg}=5m/s[/tex]
From the question we are told that:
initial Velocity [tex]V_1=5m/s[/tex]
initial Time [tex]T_1=4min=>240sec[/tex]
Final Velocity [tex]V_2=4m/s[/tex]
Final time [tex]T_2=3min=>180sec[/tex]
a)
Generally, the equation for displacement is mathematically given by
d_t=(Initial +final) displacement
Where
initial displacement
[tex]d_1=V_1*t_1\\\\d_1=5*240[/tex]
[tex]d_1=1200m[/tex]
Final displacement
[tex]d_2=V_2*t_2\\\\d_2=5*180[/tex]
[tex]d_2=900m[/tex]
Therefore
[tex]d_t=(Initial +final) displacement[/tex]
[tex]d_t=1200+900[/tex]
[tex]d_t=2100m[/tex]
b)
Generally, the equation for Average velocity is mathematically given by
[tex]v_{avg}=\frac{d_t}{t_1+t_2}[/tex]
[tex]v_{avg}=\frac{2100m}{240+180}[/tex]
[tex]v_{avg}=5m/s[/tex]
in conclusion
The wombats total displacement is
[tex]d_t=2100m[/tex]
The average velocity during that time is
[tex]v_{avg}=5m/s[/tex]
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plese help me if u know
Answer:
The velocity is uniform (unchanging) from A to B
The velocity increases from O to A
The velocity is decreasing from B to C and C to D
Acceleration is zero from A to B because the velocity is constant
The object starts to move at O and stops at D
The brakes on your automobile are capable of slowing down your car at a rate of 4.7 m/s2. (a) If you are going 134 km/h and suddenly see a state trooper, what is the minimum time in which you can get your car under the 90 km/h speed limit
Answer:
It's should be 7.0m/s.....i hope it helps
If a diver displace water with a weight of 500N what is the upthrust on the diver?
Answer:
500 N
Explanation:
Natural bouyency will keep the diver in the same place, no matter what the mass of gfs. This means if the diver is displacing with a weight of 500 N, the upthrust will also be 500 N.
Upthrust on the diver will be 500 N
What is Upthrust?
It is the force exerted by a fluid on an object in upward direction .
Since , Upthrust = weight of the liquid displaced by a submerged part of the body
so, Upthrust = mg where m = mass of the body and
g = acceleration due to gravity
It is given weight of water displaced = 500 N
hence , Upthrust on the diver will be 500 N
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eo *Write any two uses of good condutor of heat
any two uses of good conductor of heat are
aluminium, cooper, metal are good conductor of heat and they are used for making utensils.
gold, silver, are also good conductor of heat they are used for making jewelleries.
After the experiment, scientists organize and (blank) the data.
Does anyone know what goes in the blank? Im doing a crossword puzzle and I need help, please. (/w\)
Answer:
analyze
Explanation:
A 12.0 V battery has as 80.0 Ohm
resistor attached. How much
current flows through the circuit?
(Unit = A)
Using ohms law
[tex]\\ \sf\longmapsto \dfrac{V}{I}=R[/tex]
[tex]\\ \sf\longmapsto I=\dfrac{V}{R}[/tex]
[tex]\\ \sf\longmapsto I=\dfrac{12}{80}[/tex]
[tex]\\ \sf\longmapsto I=0.15A[/tex]
help with the number 2 question
Answer:
It is frequently stated that the value of the acceleration due to gravity at the pole is larger than at the equator because the poles are closer to the center of the earth due to the earth's oblateness. ... The measured value is larger because the earth's density is not uniform but increases toward the center.
Answer:
as explained that poles have more gravitational
force (9.83m/s^2) as the poles of earth is nearer to the center because it is flat at poles
but certainly at equator is having less gravitational force (9.78m/s^2) as it is Farr from centre of earth because it is bulgded at equator.
hence, poles have more gravitational force as co.pared to that of equator.
hope this helped you
any confusion the comment it.
classify the animal hydra and plant mustard with two characters of each
Answer:
Mustard seeds, both white and brown, are nearly globular in shape, finely pitted, odourless when whole, and pungent-tasting
Image result for character of hydra
Introduction: Hydra are inconspicuous freshwater relatives of corals, sea anemones and jellyfish. All are members of the phylum Cnidaria, characterized by radially symmetrical bodies, presence of stinging tentacles and a simple gut with only one opening (gastrovascular cavity)
Explanation:
Hydra are a genus of small, fresh-water organisms that are classified under the phylum Cnidaria.the classification of mustard is
Dicotyledons
if my answer helps you than mark me as brainliest
which kind of energy does a bullet fired from the gun poseess? How is this energy stored?
Answer:
Explanation:
The type of mechanical energy possessed by bullet fired from gun is kinetic energy which is an energy possessed by an object in motion. Thus, the same energy is possessed by a moving bus
is a resistor a control device
Answer:
A voltage-controlled resistor (VCR) is a three-terminal active device with one input port and two output ports. The input-port voltage controls the value of the resistor between the output ports. VCRs are most often built with field-effect transistors (FETs). Two types of FETs are often used: the JFET and the MOSFET.
Info from Wikipedia :)
hope this helps :D
12. A measuring cylinder has 150ml. of water in it. When a stone is immersed into the measuring cylinder, the water level raised to 210cm. What is the volume of the stone?
Answer:
60ml
Explanation:
I'm going to assume you mean 210ml not centimeters. To find the volume all we do is subtract both values or with the formula [ f - i = v ] where f = final amount and i = initial amount.
210 - 150 = 60ml
Best of Luck!
The final level of water should be = 210
[tex] {cm}^{3} [/tex]
or 210 ml
━━━━━━━━━━━━━
Given:.Initial level of water = 150mlFinal level of water = 210 ml━━━━━━━━━━━━━
Need to find:Volume of stone =?━━━━━━━━━━━━━
Solution:The volume of stone will be equal to the change in level of water.
that's,
210 - 150 [tex] {cm}^{3} [/tex]
= 60[tex] {cm}^{3} [/tex]
Hence the volume of the stone is 60 [tex] {cm}^{3} [/tex]
write down the atomic numbers of nitrogen and sodium ?
Answer:
Nitrogen is 7, sodium is 11
Answer:
[tex]nitrogen = 7 \\ atomic \: number \: of \: sodium = 11 \\ thank \: you[/tex]
if rechargeable cell is being charged from a source of EMF the EMF of cell during charging is
A. always equal to its terminal potential difference
B. always greater than its terminal potential difference
C. always less than its terminal potential difference
D. either equal or less than its terminal potential difference
Answer:
a
Explanation:
I think bec. I am in small school
PLS HELP PHYSICS
Use the list to answer the question.
potassium, Group 1
calcium, Group 2
iodine, Group 17
neon, Group 18
Which two elements in the list would bond together based on their ionic charges?
(1 point)
potassium and neon
potassium and iodine
calcium and neon
calcium and potassium
Answer:
It is Potassium and iodine
A small dog is 10 kg on the surface of the Earth. What is the
dog's weight, in N, on the moon?
Answer:
4 kg
Explanation:
because when you go the moon you lose 6 times your weight because of the gravitational pull
Answer:
16.3333333 newtons
Explanation:
on earth it would 98 newtons
what does the symbol 'Mg' represent?
Answer:
[tex]the \: symbol \: mg \: represent \: magnesium \\ thank \: you[/tex]
Answer:
Magnesium.
I hope it's helps you