Answer:
First, remember the conservation of energy.
We can define the kinetic energy as:
K = (1/2)*m*v^2
where m is the mass, and v is the velocity.
The velocity of the person is 6m/s, and the mass is unknown.
Now, when the person rides the skateboard, this kinetic energy must remain constant, if M is the mass of the skateboard, the speed after the person rides ir will be:
K' = (1/2)*(m + M)*v'^2
Where v' is the new velocity.
In this case, we can suppose that the skateboard has really small mass compared with the person.
M < < m
then:
(m + M) ≈ m
then:
K' = (1/2)*m*v'^2 = K = (1/2)*m*v^2
from that equation, we can conclude that:
v' = v
Then if the velocity before riding the skateboard was 6m/s, then after would be also 6m/s.
A moving object has 20 Joules of potential energy and has a mass of 10 kilograms. How fast is the object moving in meters per second?
if you are pushing a box with a force of 200n and there is a force of 7 n on the box due to sliding friction, what is the net force on the box
Which of the following most likely describes a Group 10 element?
O Good conductor of heat
O Gas at room temperature
O A member of the carbon group
O Poor conductor of electricity
Answer:
A. Good conductor of heat
Explanation:
The group 10 elements are a group of chemical elements as part of VIII elements and they include nickel, platinum, palladium etc. These group of chemical elements are all d-block transition metals, highly ductile and lustrous and are mostly white to light grey in color.
The statement which most likely describes a Group 10 element is that they are good conductor of heat because they have some of the chemical and physical properties of metals.
explain what happens when two light waves traveling from the same direction of displacement meet.
Hint: think about how the crests and troughs of these waves might be affected
Answer:
They hit each other
Explanation:
)A ball is hit straight up with an initial speed of 50 meters per second. What is the speed of the ball 3 seconds after it is hit? [Neglect friction.]
Answer:
The velocity of the ball after 3 seconds it is hit, is 20.6 m/s
Explanation:
Given;
initial velocity of the ball, u = 50 m/s
time of the upward motion of the ball, t = 3 seconds
The velocity of the ball after 3 seconds is calculated by applying the following kinematic equation;
v = u - gt
where;
g is acceleration due to gravity = 9.8 m/s²
v = 50 - (9.8 x 3)
v = 50 - 29.4
v = 20.6 m/s
Therefore, the velocity of the ball after 3 seconds it is hit, is 20.6 m/s
A rocket is shot out of a navy battleship to test a new rocket. It takes 16 seconds for the rocket
to reach its destination after leaving the barrel. If its final velocity was found to be 200 m/s,
then what was the rocket's acceleration?
A. 8m/s squared
B. 12 m/s squared
C. 12.5 m/s squared
D. 16m/s squared
Is the speed of water molecules different in hot
and cold water?
3. An object accelerates from rest, with a constant acceleration of 4.5 m/s, what will its
velocity be after 30 s?
An object accelerates from the rest, which means that the initial speed of the object is 0 m/s, so the final velocity after 30 seconds will be equal to 135 m/s.
What is acceleration?Acceleration refers to the rate of change in both speed and direction of velocity over time. When something moves slower or faster in a straight line, it is said to have been accelerated. So because direction is always shifting, motion on a circular accelerates even while the speed is constant. Both factors add to the acceleration for every other types of motion.
It is a vector quantity, since acceleration has a magnitude and a direction. Another vector quantity is velocity. The velocity vector change during a certain period of time, split by that period of time, is the concept of acceleration.
The given information in the question is,
Initial speed, u = 0 m/s
Time, t = 30 s
Acceleration, a = 4.5 m/s²
Use the equation of motion,
v = u + at
v = 0 + (4.5)(30)
v = 135 m/s
Therefore, the final velocity of the object will be 135 m/s.
To know more about acceleration:
https://brainly.com/question/12550364
#SPJ2
A rock is dropped from a cliff 80m above the ground. How long does it take to reach the ground ?
Answer:
4.04 s
Explanation:
From the question given above, the following data were obtained:
Height (h) = 80 m
Acceleration due to gravity (g) = 9.8 m/s²
Time (t) =?
The time taken for the rock to get to the ground can be obtained as shown below:
h = ½gt²
80 = ½ × 9.8 × t²
80 = 4.9 × t²
Divide both side by 4.9
t² = 80/4.9
Take the square root of both side
t = √(80/4.9)
t = 4.04 s
Thus, it will take 4.04 s for the rock to get to the ground.
The total Kinetic and Potential energy of all the particles in an object is called
Answer:
Internal energy
Explanation:
A student in Europe performs the same experiment, but the AC frequency there is 50 Hz. How different length of sensitized tape will he need in order to get 25 spark marks, compared to the length of your tape for the same number of marks? Give the result in centimeters.
Answer and Explanation:
The computation is shown below:
The ac frequency in the United States is 60 Hz
The ac frequency in Europe is 50 Hz
So,
Time for 25 spark in United stated is 25 ÷ 60 s
Time for 25 spark in Europe is 25 ÷ 50 s
Now
Tape length in United States is
= 0.5 × 9.8 × (25 ÷ 60)^2
= 0.85 m
= 85 cm
And,
Tape length in europe is
= 0.5 × 9.8 × (25 ÷ 50)^2
= 1.225 m
= 122.5 cm
So, As it can be seen that
= 122.5 cm - 85 cm
= 37.5 cm
Europe has 37.5 cm more than in the United States
A car started its motion from rest and accelerated for 6 seconds, with the acceleration of 4 m/s2. Then it decelerated for 5 seconds, with the acceleration of -1.6 m/s2. What was the velocity of the car after 6+5 seconds?
I NEED LOTS OF HELP ON THIS
Which types of rocks (igneou, sedimentary, metamorphic) tend to have crystalline textures? How does this texture form?
Answer:
metamorpic rock
Explanation:
it has a crystallin textures
A car is traveling at a constant speed of 24 meters per second when all of a sudden the driver notices a deer 60 meters in front of him. Given that he has a reaction time of 1.2 seconds and that he can slow down at a rate of 6 m/s2, does he hit the deer? If so, at what speed does he hit the deer?
Answer:
[tex] {v2 }^{2} - {v1}^{2} = 2a(x2 - x1)[/tex]
[tex] - {24}^{2} = 2( - 6)(x2)[/tex]
[tex]x2 = 48[/tex]
x2 is distance after slow down. now we should calculate distance of reaction time.
[tex]d = tv[/tex]
[tex]d = (1.2)(24) = 28.8[/tex]
d + x > 60 ==> he hits the deer. now calculate hit speed.
[tex] {v2}^{2} - {24}^{2} = 2( - 6)(31.2)[/tex]
[tex] {v2}^{2} = 201.6[/tex]
URGENT! Why are vectors important to the concept of relative velocity?
Answer:
Explanation:
In physics, vectors are useful because they can visually represent position, displacement, velocity and acceleration. When drawing vectors, you often do not have enough space to draw them to the scale they are representing, so it is important to denote somewhere what scale they are being drawn at.
A soccer ball kicked with a force of 14.7 N
accelerates at 7.3 m/s2 to the right.
What is the mass of the ball?
Answer in units of kg.
Answer:
The answer is 2.01 kgExplanation:
The mass of the ball can be found by using the formula
[tex]m = \frac{f}{a} \\ [/tex]
where
f is the force
a is the acceleration
From the question we have
[tex]m = \frac{14.7}{7.3} \\ = 2.01369863...[/tex]
We have the final answer as
2.01 kgHope this helps you
Answer:
The answer is 2.01 kg.
Explanation:
The displacement during the interval from t = 0 s and t = 4 s is 10 m 10 m 20 m 20 m 25 m 25 m 40 m 40 m cannot be determined without knowing starting point
Answer:
Cannot be determined
Explanation:
Given
Interval: 0s to 4s
Required
Determine the displacement
The given information (i.e. time interval) can not be used to determine the displacement of the body.
To solve for displacement, we need the starting point, the direction moved and the distance moved in each direction.
So, it's either the question is incomplete or the answer to the question is option (e) cannot be determined
Which one of Newtons laws of motion best explains why the dishes do not move when the table cloth is removed?
AND
A rocket lifting off the ground into space can be explained by (which one of newtons laws?)
Answer:
1. Newtons first law (everything in motion/rest stays in motion/rest untill acted up by and unbalanced force).
2. Newtons third law (every reaction has an equal and opposite reaction)
Explanation:
what is the frictional force needed to slow an object in motion
Answer:
kinetic friction
Explanation:
A hockey puck slides across the ice at a constant speed.
Which of the following is true?
1. It is in equilibrium.
2. The puck is at rest.
3. The puck is moving and thus not in equilibrium.
4. None of these
5. The puck can be considered neither at
rest nor in equilibrium.
As a hockey puck slides across the ice at a constant speed, it is n equilibrium. The correct option is 1.
What is equilibrium?Chemical equilibrium is the condition in which both the products and reactants are prevalent in concentrations that have no further tendency to change with time, resulting in no observable change in the system's properties.
When a reaction and its reverse reaction proceed at the same rate, this is referred to as chemical equilibrium.
Both forward and reverse reactions occur as a system approaches equilibrium. The forward and reverse reactions are proceeding at the same rate in equilibrium.
It is in equilibrium because it achieves dynamic equilibrium by moving in a straight line at constant speed. The net forces are equal to zero.
Thus, the correct option is 1.
For more details regarding chemical equilibrium, visit:
https://brainly.com/question/4289021
#SPJ2
What specific object do you think of when you hear "an object in motion"?
(Example: I think of a soccer ball on a soccer field!)
Answer:
I think of somone throwing a ball or a ball rolling off of a table.
Explanation:
HELP ASAP!!!!!
7. Describe two events that occur on Earth that you
would not expect to find on Mars because of the
lack of plate movements.
Answer:
life, the core of mass is made of iron, sulphur i think
A stone is projected vertically upwards with a velocity of 12ms'. Calculate or find:
a) How long it took the stone to reach its maximum height.
b) Maximum height reached by the stone.
Answer:
The acceleration of the stone will be -9.8 m/s^2, because of the acceleration of earth's gravity, the initial velocity will be 12 m/s, and the final velocity will be 0 m/s. Therefore, we can solve using a kinematic equation to solve the problems:
a)
Final Velocity = Initial Velocity + Acceleration * Time
0 = 12 + -9.8*t
-12 = -9.8*t
t = 12/9.8 ≈ 1.224
Therefore, the time is equal to 12/9.8 ≈ 1.2245 seconds.
b)
Displacement = (Initial Velocity + Final Velocity)/2 * Time
d = (12+0)/2*1.2245
d = 6*1.2245
d = 7.347
Therefore, the maximum height is approximately equal to 7.347 meters.
how many electrons would be in an atom of carbon that has six protons and six neutrons?
What is the frequency of this wave?
O 1
)2.
O 3
o 4
Answer:
The frequency, represented by the Greek letter nu (ν), is the number of waves that pass a certain point in a specified amount of time. Typically, frequency is measured in units of cycles per second or waves per second. One wave per second is also called a Hertz (Hz) and in SI units is a reciprocal second (s−1).
PLEASE help me with 1-8 !!
1. A wagon, initially traveling at a constant 9.7 m/s, starts going down a hill that creates an acceleration of 4.8 m/s2.
What is the wagon's velocity 6.9 s after it starts accelerating down the hill?
Answer: 24 m/s
Explanation:
PLEASE HELP WILL MARK A BRAINLIEST
Which statement about polymers is true?
A. Polymers are substances that have relatively large molecules.
B. Oil and gas are the starting materials for making all polymers.
C. Fabrics such as cotton and silk are synthetic polymers.
D. All polymers are obtained from living organisms.
Answer:
The answer is (A) "Polymers are substances that have relatively large molecules."
Polymer, any of a class of common or synthetic substances made out of very large molecules, called macromolecules, that are products of less complex synthetic units called monomers. Polymers make up a considerable lot of the materials in living beings, including, for instance, proteins, cellulose, and nucleic acids. In addition, they constitute the premise of such minerals as diamond, quartz, and feldspar and such man-influenced materials as solid, glass, to paper, plastics, and rubbers.
Answer:
I hope this helps
Explanation:
Which shows the correct pathway for nitrification? A. Ammonium Æ Nitrite Æ Nitrate B. Ammonia Æ Nitrite Æ Nitrate C. Ammonia Æ Nitrate Æ Nitrite D. Both A and
Answer:
Both Option A and B.
Explanation:
Both Option A and B are correct because Nitrification is the process whereby ammonium or ammonia is oxidized by ammonia oxidizing bacteria or nitrosofying bacteria like nitrosomonas, niitrosococcus into nitrite and also the process whereby nitrite is oxidized to nitrate by nitibacter bacteria
Distance vs. Time
80
70
60
B
50
Distance (m)
40
А
30
20
10
10 20
30 40 50
Time (s)
60
70
80
1. How far has the student walked in 25 seconds?
2. Describe the motion of the student from 25 seconds to 60 seconds.
3. How long did it take the student to walk 40 meters?
4. What is the independent variable?
5. What is the dependent variable?
Answer:
1. 50m
2. they are motionless
3. 20s
4. time
5. distance