Answer:
Acceleration is 2.78 m/s²
Explanation:
Since the car is from rest, initial velocity, u is zero.
from first newton's equation of motion:
[tex]{ \bf{v = u + at}} \\ [/tex]
v is final velocity
u is initial velocity
a is acceleration
t is time
70 km/h is (70 × 1000 ÷ 3600) m/s = 19.44 m/s
[tex]{ \sf{19.44 = 0 + (a \times 7)}} \\ { \sf{7a = 19.44 }} \\ { \sf{a = 2.78 \: {ms}^{ - 2} }}[/tex]
Give reason for the following:
a) An inflated balloon was pressed against a wall after it has been rubbed with a
piece of synthetic cloth. It was found that the balloon sticks to the wall.
b) When an object is thrown up, it comes back to ground.
c) Mountaineers suffer nose bleeding at higher altitudes.
d) Foundations of high rise buildings are kept wide.
e) Deep sea divers or high altitude fliers wear special suits.
f) Walls of a dam are thickened near the base.
a) An inflated balloon was pressed against a wall after it has been rubbed with a piece of synthetic cloth. It was found that the balloon sticks to the wall. This is because a positive and negative electric charge is produced, therefore the balloon sticks to the wall.
b) When an object is thrown up, it comes back to ground because of gravitational attraction force of earth.
c) Mountaineers suffer nose bleeding at higher altitudes because the oxygen level decreases with increase in altitude, which the body cannot adjust.
d) Foundations of high rise buildings are kept wide because more is the area of contact, less is the pressure efforts. So, foundations are wide so as to decrease the possibility of the building from falling down.
e) Deep sea divers or high altitude fliers wear special suits so as prevent their body from being crushed by the water pressure. Since water pressure is maximum at deep seas and oceans, therefore, more is the risk of being injured.
f) Walls of a dam are thickened near the base so that the dam can handle the kinetic energy pressure and prevent itself from breaking down, which if not, can lead to flooding.
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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
What is environment
Answer:
environment is the situation of the place
Explanation:
i think helping you... have a great day:)
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
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 mewrite 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]
define 1 standard meter
Explanation:
The standard meter is the length of the path travelled by the light in vacuum during a time interval of 1/299792 of a second. The meter is the length of the path travelled by light in vacuum during a time interval of 1/299792 of a second. 1 m is about 39.37 inches.
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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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
Explain ALL THREE of Newton’s Laws in your own words.
Explanation:
(1) Every object moves in a straight line unless acted upon by a force. (2) The acceleration of an object is directly proportional to the net force exerted and inversely proportional to the object's mass. (3) For every action, there is an equal and opposite reaction.
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 car of mass 900 Kg is moving with a velocity of 10 m/s. It is brought to rest at 25 m distance by applying the brakes. Calculate the acceleration. Why is it negative? How much force is required to stop the car?
Answer:
Assumption: the acceleration of this vehicle is constant until it comes to a stop.
Acceleration: [tex](-2)\; \rm m\cdot s^{-2}[/tex].
The acceleration of this vehicle is negative because the velocity of this vehicle is decreasing over time.
Explanation:
Let [tex]u[/tex] denote the initial velocity of this vehicle. [tex]u = 10\; \rm m\cdot s^{-1}[/tex].Let [tex]v[/tex] denote the final velocity of this vehicle. [tex]v = 0\; \rm m\cdot s^{-1}[/tex] as the vehicle has come to a stop.Let [tex]x[/tex] denote the displacement of this vehicle. [tex]x = 25\; \rm m[/tex].Let [tex]a[/tex] denote the acceleration of this vehicle. The value of [tex]a\![/tex] needs to be found.Assume that the acceleration of this vehicle, [tex]a[/tex], is constant. The SUVAT equations would apply.
The time [tex]t[/tex] required for braking is neither given nor required. Hence, make use of the SUVAT equation [tex]v^{2} - u^{2} = 2\, a\, x[/tex] to relate [tex]u[/tex], [tex]v[/tex], [tex]a[/tex], and [tex]x\![/tex].
Rearrange this equation to find an expression for [tex]a[/tex], the acceleration of this vehicle:
[tex]\begin{aligned}a &= \frac{v^{2} - u^{2}}{2\, x} \\ &= \frac{(0\; \rm m\cdot s^{-1})^{2} - (10\; \rm m \cdot s^{-1})^{2}}{2\times (25\; \rm m)} \\ &= \frac{0^{2} - 10^{2}}{2 \times 25}\; \rm m \cdot s^{-2} \\ &= -2\; \rm m\cdot s^{-2}\end{aligned}[/tex].
When the rate of change of a value is greater than [tex]0[/tex], that value would become larger over time.When the rate of change of a value is equal to [tex]0[/tex], that value would be constant.When the rate of change of a value is smaller than [tex]0[/tex], that value would become smaller over time.
Acceleration is the rate at which velocity changes over time.
The velocity of the vehicle in this question is getting smaller over time. Hence, the rate of change of the velocity of this vehicle (that is, the acceleration of this vehicle) would be a negative number.
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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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
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 mass of water in grams will fill a tank 100cm long, 50cm wide, 30cm high?
Answer:
150,000grams
Explanation:
100*50*30=150,000
Also 1ml water= 1 grams
Answer:
150,000³
Process:
You multiply 100cm x 50cm x 30cm. The reason you do this is because the "mass" will be the volume of the tank of water. A "small 2" would represent a two dimensional area, whereas the "small 3" would represent a 3 dimensional area.
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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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
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
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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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Which of the following is true about scientific laws?
Answer: Scientific theories are never proven.
Explanation:
If an elephant has a mass of 6,000 kg,
what would its mass be on the moon?
As you just said, the elephant "... has a mass of 6,000 kg ...". It doesn't matter where.
2000 Pieces of paper are used everyday at a local school. Each piece of paper is 600cm^2. Convert the area of all the paper used in one day to m^2. The answer is 120 m^2 someone please help me understand this with dimensional analysis?
2. 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]
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 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]
how can we use data to predict future motion
Answer:
Explanation:
How can we predict future motion?
Image result for how can we use data to predict future motion
Make observations and/or measurements of an object's motion to provide evidence that a pattern can be used to predict future motion. Clarification Statement: Examples of motion with a predictable pattern could include a child swinging in a swing, a ball rolling back and forth in a bowl, and two children on a see-saw.
A woman leaning over the railing of a tall bridge accidentally drops her cell phone. If
the bridge is 39.39 m high, how long will it take the phone to hit the river below the
bridge?
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.
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