Question:
A race car starts from rest and speed up uniformly to the right until it reaches a maximum velocity of 60m/s in 15 secs
Answer:
4m/s²
Explanation:
The acceleration of a body in uniform motion can be found by using one of the equations of motion as follows;
v = u + at ------------------(i)
Where;
v = final velocity of the body
u = initial velocity of the body
a = acceleration of the body
t = time taken for the motion
From the question, the body is the race car and has the following:
v = 60m/s²
u = 0 [since the car starts from rest]
t = 15 secs.
Now, substitute these values into equation(i) as follows;
60 = 0 + a(15)
60 = 15a [Divide through by 15]
[tex]\frac{60}{15}[/tex] = [tex]\frac{15a}{15}[/tex]
a = 4
Therefore, the acceleration of the race car is 4m/s²
A train travels a 400-km route and makes five stops in seven hours. Which equation is used to calculate the train’s average speed?
A.
Average speed = Sum of instantaneous speeds
B.
Average speed = Total distance x Total time
C.
Average speed = Total distance + Total time
D.
Average speed = Total distance ÷ Total time
*You water some plants with 4 different types of water (salt water, regular water, sugar water and distilled water). After a two-week period, the height of the plants is measured.
1) Independent Variable (IV):
2)Dependent Variable (DV):
3)Constants:
4)Control:
Answer:
Please find the answer in the explanation
Explanation:
Given that some plants were watered with 4 different types of water (salt water, regular water, sugar water and distilled water). After a two-week period, the height of the plants is measured.
1.) The Independent Variable (IV) are the different types of water
2)Dependent Variable (DV) are the height of the plant. Dependent variable depends on the independent variable.
3)Constant is the unchanged parameter which is the period - the two weeks
4)Control: is the quantity of water used.
what are the 5 native elements?
Answer:
platinum, iridium, osmium, iron, zinc
A watch manufacturer claims that its watches gain or lose no more than 8 seconds in a year. How accurate are these watches, expressed as a percentage?
Answer:
Accurate at 99.9999746%
Explanation:
First of all, let's calculate how many seconds we have in a year which has 365 days.
1day = 24 × 60 × 60 seconds = 86400 s
Thus, for 365 days, we have;
86400 × 365 = 31536000 seconds
Now, since 1 year has 31536000 seconds, let's find the ratio of efficiency.
We are told that the watch manufacturer claims that its watches gain or lose no more than 8 seconds in a year. Thus, efficiency is given by;
Efficiency = (8/31536000) × 100% = 0.00002536783 %
Thus, it will be be accurate at;
100% - 0.00002536783% ≈ 99.9999746%
action and reaction are equal in magnitude and opposite in direction then why do they not balance each other.
Answer:
Newton’s third law of motion states that every action has an equal and opposite reaction. This indicates that forces always act in pairs. Reaction forces are equal and opposite, but they are not balanced forces because they act on different objects so they don’t cancel each other out.
A force of 25N acts on a body of mass 9 kg. calculate the acceleration produced
Answer:
2.7
Explanation:
[tex]Force = 25N\\mass = 9 kg\\acceleration = ?\\\\Force = mass \times acceleration\\\frac{Force}{mass}= acceleration\\ \\Acceleration = \frac{25}{9} \\\\Acceleration = 2.7[/tex]
A substance has density ρ, mass m, and volume V. If the volume is tripled, what is the new mass?
Since the density of the substance is ρ (rho),
==> every cm³ of this substance has ρ grams of mass.
Then
==> V cm³ of it has ρV grams of mass. That's ' m '.
and
==> 3V cm³ of it has 3ρV grams of mass. That's ' 3m '.
An egg falls out of a nest of a tree. It freefalls for 1.5 seconds, and then hits the ground. From how high up did the egg fall?
Answer:
11.025m
Explanation:
Using kinematics,
u = Initial velocity = 0.
t = Time taken = 1.5sec.
a = Acceleration from gravity = 9.8m/s^2
Distance = s
= ut + 1/2 * a * t^2
= 0 + 1/2 * 9.8 * (1.5)^2
= 11.025m
The egg fall from the nest of a tree is 11.025 m.
To find height from where the egg fall, the given values are:
Time taken t = 1.5 seconds.
What is the distance of the egg fall? The egg was falling from the nest of a tree.By knowing the concept of Kinematics,
For a particle moving with a constant acceleration, its displacement after a time period is given by
s = ut +1/2 at²
where, u - initial velocity,
t - Time,
a - acceleration.
As u is the Initial velocity = 0.
t = 1.5s
Acceleration from gravity = 9.8m/s²
Here, Distance = s
Substituting all the values in the formula,
s = ut + 1/2 ( a × t²)
= 0 + 1/2 × 9.8 × (1.5)²
Distance s = 11.025m
So, the distance the egg fall from a nest of a tree is s = 11.025 m.
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a kayaker moves 32 meters northward then 6 meters southward finally 24 meters northward
Answer:
50m [N]
Explanation:
Think of these directions as if they were on a 2D plane. (if you're talking about displacement)
If you go 32m [N] then 6m [S], it's like you're moving backwards (-). (thus, 32n-6s=26m [N])
Next, you go north again, so moving forwards (+). (thus, 26n+24n=50m [N])
The distance he paddled was (32m + 24m + 6m) = 56 meters.
His displacement after that was (32m - 6m + 24m) = 50 meters north.
2. A car is moving south. It is getting faster. In which direction is the acceleration?
North
South
hy
Up
Down
A straw is placed in a cup of water. The straw has a diameter of 5 mm, the contact angle is 60 degrees and the surface tension of water is 0.073 Nm. Calculate the change in elevation between the water surface in the cup and that in the straw.
Answer:
The change in elevation is 0.0029mmExplanation:
This problem is on the capillary action of water and tube
we are going use the formula below for the rise in liquid level
h= 2Tcos∅/rgρwhere h= height of liquid level in the capillary tube
T= surface tension = 0.073 Nm
∅= angle of contact = 60 degrees
r= radius of bore of capillary tube = 5/2= 2.5 mm to m= 2.5/1000=
2.5*10^-3
g= acceleration due to gravity = 9.81 m/s^2
ρ= density of the liquid (assume water 1000 kg/m³)
we can now substitute to solve for h
[tex]h=\frac{2*0.073cos60}{ 2.5*10^-^3*9.81*10^3} \\\\h=\frac{2*0.073*0.5}{ 2.5*9.81}\\\\h=\frac{0.073}{ 2.5*9.81}\\\\h=\frac{0.073}{ 24.525}\\\\h=\frac{0.073}{ 24.525}\\\\h= 0.0029\\h= 2.9*10^-^3mm[/tex]
A driver starts her car and steps on the gas pedal. The car gradually
accelerates to 60 km/hr and maintains this velocity. A few minutes later, the driver suddenly slams on the brakes to avoid hitting a squirrel. As the car comes to a stop, the driver's body appears to lurch forward in the seat until it is restrained by the seat belt.
Which graph best represents the motion of a car described in the paragraph above?
Graph C
Graph D
Graph A
Graph B
If Angela ran to the bus and back to where she started what distance would she travel ?
Answer:
Distance = 30 m
Explanation:
Since the position of the bus is at zero, and distance is a scalar quantity. That is, we are only concerned about the magnitude
If Angela ran to the bus and back to where she started, the distance travelled will be:
Distance = 15 + 15 = 30 m
But her displacement will be:
Displacement = 15 - 15 = 0.
A perfect bouncy ball would continue bouncing the same height forever. But in reality, the ball stops bouncing because energy is "lost" to ...
A.sound energy
B.compression of the ball
C.heat energy absorbed by the ball
D.all answers are true
Answer:
D. all answers are true
The ball stops bouncing because energy is to sound energy, compression of the ball, and heat energy absorbed by the ball. Thus, the correct option is D, i.e. all of the above.
How energy is lost in a physical state?The law of conservation of energy, it states that energy can neither be created nor be destroyed in any physical state, although it may get transformed into another form.
The same principle is followed by the bouncing ball. In a closed system, its energy is never lost but it may get transformed into sound energy, heat energy which is absorbed by the ball, and compression which stimulates the process of bouncing the ball.
It is a principle of physical science that due to some characteristics the energy may be transformed into other form.
Therefore, the correct option is D, i.e. all of the above.
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What actions are permissible when you are graphically adding one vector to another?
Answer:
1. Which of the following actions is permissible when you are graphically adding one vector to another:
Explanation:
: move the vector, rotate the vector, change the vector's length?
When you graphically add one vector to another, you can only move the vector as long as you don't modify its length or the direction it points in.
What are vector quantities?In physics, a vector is a quantity with both a magnitude and a direction. It is often represented by an arrow whose length is proportional to the magnitude of the quantity and whose direction is the same as that of the quantity.
A vector does not have position, while having magnitude and direction. In other words, a vector's shape is unaltered if it is shifted parallel to itself as long as its length is unaltered.
Hence, when you are graphically adding one vector to another, permissible action is move the vector as long as you don't modify its length or the direction it points in.
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action and reaction are equal in magnitude and opposite in direction then , why do not they balance each other
Explanation:
Newton’s third law of motion states that every action has an equal and opposite reaction. This indicates that forces always act in pairs. Reaction forces are equal and opposite, but they are not balanced forces because they act on different objects so they don’t cancel each other out.
only 90% can dothis plz helpme i will give brainliest brainliest brainliest brainliest brainliest brainliest brainliest brainliest brainliest brainliest brainliest Why magnetic bodies lose magnetic force? Why a nail gets magnetized when kept close to magnet? Why two pins attracted by bar magnet maintain distance between their ends? Why magnet do not have ,magnetic force in middle?
The force exerted by a magnet is called The push or pull of magnetism can act at a distance, which means that the magnet does not have to touch an object to exert a force on it. ... In fact, magnetism is the result of a moving electric charge.Explanation:
thanks! i need the brainliest to level up :)
1. Heat causes magnetic bodies to lose their magnetic force. For each material of magnet, there is a Curie temperature, or temperature at which the heat will destroy the polarization of the material, causing it to loses its magnetic properties.
2. In unmagnetized materials the domains are randomly aligned in different directions and cancel each other out. In a magnet, all the domains are oriented in the same direction. In the case of a nail, the domains can be aligned in the same direction causing the nail to become magnetic.
3. because after got attracting they will also got act as magnets since they would also get North and South poles so in the case of same poles they had repulsion.
4. We know that magnetic fields exert forces on moving electrons for example. ... When you are in the middle of the magnet, the metal object is being pulled more or less equally in both directions, and so the result is that the object doesn't really feel a force in either direction, they cancel each other out.
i hope this helps you!! <3
How is data recorded in science?
Answer:
Yes
Explanation:
You need data to be able to compare experiments and come up with predictions.
A point charge of +3 C is located at the origin of a coordinate system and a second point charge of -6 C is at x = 1.0 m. At what point on the x-axis is the electrical potential zero?
Answer:
The point at which the electrical potential is zero is x = +0.33 m.
Explanation:
By definition the electrical potential is:
[tex] V_{E} = \frac{K*q}{r} [/tex]
Where:
K: is Coulomb's constant = 9x10⁹ N*m²/C²
q: is the charge
r: is the distance
The point at which the electrical potential is zero can be calculated as follows:
[tex] V_{1} + V_{2} = 0 [/tex]
[tex] K(\frac{q_{1}}{r_{1}} + \frac{q_{2}}{r_{2}}) = 0 [/tex] (1)
q₁ is the first charge = +3 mC
r₁ is the distance from the point to the first charge
q₂ is the first charge = -6 mC
r₂ is the distance from the point to the second charge
By replacing r₁ = 1 - r₂ into equation (1) we have:
[tex]K(\frac{q_{1}}{1 - r_{2}} + \frac{q_{2}}{r_{2}}) = 0[/tex] (2)
By solving equation (2) for r₂:
[tex]r_{2} = \frac{q_{1}}{q_{1} - q_{2}} = \frac{3 mC}{3 mC - (-6 mC)} = +0.33 m[/tex]
Therefore, the point at which the electrical potential is zero is x = +0.33 m.
I hope it helps you!
Since the two charges are placed on the x-axis. Then, the electric potential is zero at the distance of 0.66 m from the second point charge on the x-axis.
What is electric potential?The electric potential at any point is the amount of work needed to move a unit positive charge from infinity to that point.
Given data-
The magnitude of a point charge is, Q = + 3 C.
The magnitude of the second point charge is, Q' = -6 C.
The distance between the two charges is, x = 1.0 m.
The expression for the net electric potential due to both the charges is,
[tex]V = \dfrac{k \times Q}{x} +\dfrac{k \times Q'}{x-y}[/tex]
here,
k is the Coulomb's constant.
y is the distance from the second point charge on the x-axis, where the net potential is zero.
Now, for zero net electric potential due to both the charges we have,
[tex]0 = \dfrac{k \times Q}{x-y} +\dfrac{k \times Q'}{y}\\\\\\-\dfrac{k \times Q'}{y}=\dfrac{k \times Q}{x-y}[/tex]
Solving as,
[tex]-\dfrac{(-6)}{y}=\dfrac{3}{1-y}\\\\6-6y=3y\\\\y =0.66\;\rm m[/tex]
Thus, we can conclude that the electric potential is zero at the distance of 0.66 m from the second point charge on the x-axis.
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Question 8 of 10
Which term refers to a variable that a scientist adjusts during an experiment?
A. Dependent variable
B. Manipulated variable
C. Responding variable
D. Empirical variable
Answer:
B. Manipulated Variable
Answer:responding variable
Explanation:
Apex users
Select the correct answer.
Matthew uses the combine harvester to harvest his crops. Which PPE should Mathew use?
А. сар
B.
earmuffs
C. gloves
D. respirator
E. safety glasses
Answer:
Matthew should use the safety glasses as his PPE.
Explanation:
What is the acceleration of a car that goes from zero to 60m/s in 15s?
Answer:What is the acceleration of a car that moves from rest to 15.0 m/s in 10.0 s? Vi=0, vf= 15.0 m/s,t=10.0s, a=? a= vf =vi/tA=15.0m/s-0m/s/10.0s = 15.0s/10.0s m/s*1/s =1.50 m/s^2 11.
Explanation:
Help me plz science middle school
The correct answer is A. He created a way of naming organisms based on genus and species
Explanation:
Carl Linnaeus created a simple but precise system for naming organisms of any species and kind. This system was known as binomial nomenclature and the names of organisms depend on two main elements: the genus and the species. The first element is a broad category that covers species with a common origin, and the second one is the species, which describes organisms that can reproduce and share many common features including DNA sequence. According to this, the correct answer is A.
Given the information in the velocity vs. time graph,
what is the displacement of the object after 1 second?
m
After 3 seconds?
m
After 5 seconds?
Answer:
Given the information in the velocity vs. time graph, what is the displacement of the object after 1 second?
3m
After 3 seconds?
9m
After 5 seconds?
15m
Explanation:
The displacement of the object after 1-second would be 3 m, the displacement of the object after 3 seconds would be 9 m, and the displacement of the object after 5 seconds would be 15 sec
What is Velocity?The total displacement covered by any object per unit of time is known as velocity. It depends on the magnitude as well as the direction of the moving object. The unit of velocity is meter/second.
The mathematical relation between displacement and velocity is given by
Total displacement=Total time×velocity
As given in the problem A velocity-time graph is shown, displaying the behavior
Velocity from the velocity time graph
velocity =3 m/s
As we know the area under the velocity time curve represents the displacement covered by the object
displacement of the object after 1-second = 3×1
= 3 m
displacement of the object after 3-second = 3×3
= 9 m
displacement of the object after 5-second = 3×5
= 15 m
Thus, The displacement of the object after one second, three seconds, and five seconds would be three meters, nine meters, and fifteen meters, respectively.
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on, Inc., publishing as pe
6. Circle the letter before each element that is a gas at room temperature.
a. carbon
c. mercury
d. nitrogen
b. oxygen
A car goes from 30 m/s to 20 m/s in 2 seconds. What is the acceleration of the car in m/s2?
Answer:
[tex] \boxed{\sf Acceleration \ of \ the \ car = -5 \ m/s^2} [/tex]
Given:
Initial speed (u) = 30 m/s
Final speed (v) = 20 m/s
Time taken (t) = 2s
To Find:
Acceleration (a) of the car
Explanation:
From equation of motion we have:
[tex] \boxed{ \bold{v = u + at}}[/tex]
By substituting value of v, u & t in the equation we get:
[tex]\sf \implies 20 = 30 + a(2) \\ \\ \sf \implies 2a + 30 = 20 \\ \\ \sf \implies 2a = 20 - 30 \\ \\ \sf \implies 2a = - 10 \\ \\ \sf \implies a = - \frac{10}{2} \\ \\ \sf \implies a = - 5 \: m {s}^{ - 2} [/tex]
[tex] \therefore[/tex]
Acceleration (a) of the car = -5 m/s²
How can you use the position-time graphs for two in-line skaters to determine if and when one in-line skater will pass the other one?
Explanation:
Position-time graphs measure/express the position of a skater over time relative to the start or finish of the race (depends on how it is used). Note: are the skaters in line vertically or horizontally? Like is one directly behind the other or are they next to each other?
If the two skaters are in line horizontally with each other, then their position will be the same relative to the start or finish of the race. This means if one passes the other one, the position would be different for all times after they pass. On the graph, it would look like one single line at the start (as position is same) which splits into 2 (representing the new difference in position due to 1 passing the other.
If the two skaters are in line vertically, their lines on the graph will appear parallel to each other (assuming they are going same speed) because the position is changing at the same rate, one is just reaching the same point after the other. If the skater behind overtakes the one in front. The lines on the graph will cross and continue either in parallel but with the other line on top to represent the moment where their position is the same right before they pass and after, where the second skater is now in front.
Hope this helped!
1. In a biology experiment the number of yeast cells is determined after 24 hours of growth at
different temperatures.
a) Identify the independent and dependent variables in the experiment.
Answer:
Find the answer in the explanation
Explanation:
Given that In a biology experiment the number of yeast cells is determined after 24 hours of growth at different temperatures
The dependent variable depends on the value of the independent variable.
From the question above,
The independent variable is the temperature
While the dependent variable is the number of yeast cells
As Sam comes to a stop on his bike, he slows from 9.00m/s to 0.00m/s in 5.00 seconds. Find the average acceleration of Sam on his bike. Hint: It will be a negative number.
Explanation:
Acceleration is change in velocity over time.
a = (v − v₀) / t
a = (0.00 m/s − 9.00 m/s) / 5.00 s
a = -1.80 m/s²
Why are chloroplasts found in plant cells but NOT in animal cells?
Answer:
Its is because plants dont get sugar from eating food so, they need chloroplast to make food with the help of sunlight.Whereas animal can get sugar from the food they eat.