Trick to identify:-
Exothermic reaction has +∆H sign on product sideEndothermic reaction has -∆H sign on product side or +∆H sign on reactant sideAnswer:
In an exothermic reaction, energy is
✔ released to
the surroundings.
In an endothermic reaction, energy is
✔ absorbed from
the surroundings.
Explanation:
A boulder of mass 10 kg rolls over a cliff and reaches the beach below with a velocity of 15 m/s. Find:
a. the kinetic energy of the boulder as it lands;
b. the potential energy of the boulder when it was at the top of the cliff
c. the height of the cliff.
Answer:
formular kinetic energy=1/2 ×vI'll give brainliest
Answer: figuratively speaking both the lines for the force Q and force P is equal.
Explain why position is a dependent variable in a position versus time graph.
Answer:
Explanation:
The position depends on the time. The longer the time, the further the distance.
Which colour of light is refracted more by a prsim green or blue.explain
Answer:
The light waves are refracted as they enter and leave the prism. The shorter the wavelength of the light, the more it is refracted. As a result, red light is refracted the least and violet light is refracted the most - causing the coloured light to spread out to form a spectrum.
Explanation:
hope this helps
Answer: Neither, its actually violet aka purple. This is because it has the shortest wavelength. This is also why red light is refracted the least because it has the longest wavelength.
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An irregularly shaped stone was lowered into a graduated cylinder holding a volume of water equal to 20L. The height of water rose to 30.2mL. If the mass of the stone was 25g what was its density?
Answer:
2.45 g/mL
Explanation:
(assuming that the original volume was 20 mL and not L)
Since you know the amount of water in the cylinder before and after you placed the rock in, you can subtract them to get the volume of the rock itself. [tex]30.2-20=10.2[/tex] mL.
To get the rock's density, use the equation [tex]d=\frac{m}{v}[/tex], where m is mass and v is volume.
[tex]d=\frac{25 g}{10.2mL}\\\\d=2.45 g/mL[/tex]
How does the electric energy between two negativly charged particles change if one particles charge is increased by a factor of 2
Answer:
i dont know this one
Explanation:
sorry i wish i could help but if u look closley on that qyestion you will understand it mor
When the sum of all the forces acting on a block.
Answer:
finish the question pls
Explanation:
Solve 100N up 90N down for net force
Answer:
10 Newtons up
Hope this helps!
how many seconds does it take an object to fall 98m if it start from the rest .(using gravity 10m/s²?
Answer:
Neither.
Explanation:
After 10 seconds the object will have travelled 490.5m, not 98.1. The vertical distance covered in freefall by an object in time t is given by Distance= 1/2 x 9.81 x t^2. Simply multiplying 9.81 by the time will NOT give the distance covered.
The acceleration of the object will not change, it will always be 9.81 m/s^2. Its speed will keep increasing by 9.81 m/s every second, thats what the ‘per second squared*’ means. The speed after 10 seconds will be 98.1 m/s
To summarise, after 10 seconds, the object will have covered 490.5 metres, and it will have a final speed of 98.1 m/s. It’s acceleration will remain 9.81 m/s^2 at all times
How far from the center of the earth is the center of mass of the earth moon system?.
Answer:
With a typical distance of 384,400 kilometers separating Earth and the moon's centers, that works out to a center of mass that is roughly 379,700 kilometers from the moon's center and about 4,700 kilometers from Earth's. Explanation:
A 5.77 kg object is tied to the end of a cord and whirled in a horizontal circle of radius 355 cm. The object completes 4.4 revolutions every 6.94E-3 hours. What is the centripetal force exerted on the object?
The centripetal force exerted on the object is 25.24 N.
The given parameters:
mass of the object, m = 5.77 kgradius of the circle, r = 355 cm = 3.55 mnumber of revolutions, N = 4.4 rev for 6.9 x 10⁻³ hoursThe angular speed of the object is calculated as follows;
[tex]\omega = \frac{4.4 \ rev}{6.9 \times 10^{-3} \ h} \times \frac{1 \ h}{3600 \ s} \times \frac{2 \ \pi \ rad}{1 \ rev} = 1.11 \ rad/s[/tex]
The centripetal force exerted on the object is calculated as follows;
[tex]F =m \omega ^2 r\\\\F = 5.77 \times (1.11)^2 \times 3.55\\\\F = 25.24 \ N[/tex]
Thus, the centripetal force exerted on the object is 25.24 N.
Learn more about centripetal force here: https://brainly.com/question/20905151
Bijan wanted to find the density of a piece of metal. He weighed it. Them he measured its volume by placing it in measuring cylinder which was half-full of water. Here are his measurements: Mass of metal - 196.0 g, reading on measuring cylinder (water only) = 45 cm3 and reading on measuring cylinder (water + metal) = 68 cm3. What is the density of the piece of metal?
A 46.5-kg ball has a momentum of 57.2 kg m/s. What is the ball's speed?
Answer:
1.23 m/s
Explanation:
p=mv
57.2 = 46.5v
v= 57.2/46.5
v= 1.23
If you want to verify your answer, just insert the value of v in the equation.
If a net force of 24 Newtons is applied on an object of mass 6
kilograms, what will be the acceleration of the object?
a 2 m/s2
b. 6 m/s2
C 10 m/s2
d 4 m/s2
Answer:
4 m/s²Explanation:
The acceleration of an object given it's mass and the force acting on it can be found by using the formula
[tex]a = \frac{f}{m} \\ [/tex]
f is the force
m is the mass
From the question
f = 24 N
m = 6 kg
We have
[tex]a = \frac{24}{6} = 4 \\ [/tex]
We have the final answer as
4 m/s²Hope this helps you
How do energy transformations occur in a hydroelectric plant?
The potential energy of water is converted to mechanical energy by a turbine.
The kinetic energy of water is converted by a dam into potential energy.
The kinetic energy of water is converted by a generator into electric energy.
The potential energy of water is converted by a transformer into electric energy.
Answer:
The answer is #3: The kinetic energy of water is converted by a generator into electric energy.
Explanation:
Hydropower plants capture the energy of falling water to generate electricity. A turbine converts the kinetic energy of falling water into mechanical energy. Then a generator converts the mechanical energy from the turbine into electrical energy.
A champion weight lifter raises a 240 kg barbell a distance of 2.1 m. How much potential energy has
the barbell gained?
Answer:
Your answer is below …….
Explanation:
25. Brutus, a champion weightlifter, raises
240 kg of weights a distance of 2.35 m.
a. How much work is done by Brutus
lifting the weights?
W=Fd=mgd
= (240 kg)(9.80 m/s2)(2.35 m)
= 5.5 x 103j
b. How much work is done by Brutus
holding the weights above his head?
d=0, so no work
c. How much work is done by Brutus
lowering them back to the ground?
d is opposite of motion in part a, so
W is also the opposite, -5.5 x 103 J.
d. Does Brutus do work if he lets go of
the weights and they fall back to the
ground?
No. He exerts no force, so he does
no work, positive or negative.
If Brutus completes the lift in 2.5 s.
how much power is developed?
* = multiply
[tex]P = \frac{W}{t} = \frac{5.53 * 10x^{3} J}{2.5s} = 2.2 kW[/tex]
_____________________________________
(Hope this helps can I pls have brainlist (crown)☺️)
Why capillary happen.
Where could light travel the easiest and fastest?
A) through air
B) through empty space
C) through liquid hydrogen
Explanation:
Light travels fastest through air
Answer:
try through air
Explanation:
pease HELP Me out with this science problem no point of answering a fake question cause it will be deleted and brainly will give you a BANN WARNING!!
Answer: Increasing the amount of sugar.
Explanation: Increasing the amount of reactants increases the rate of the reaction. This is given by the collision theory, which states that a chemical reaction must involve the collisions of particles together, as well as with the walls of the container it is in. By increasing the amount of reactant in the container you are increasing the collision frequency, and the rate of the reaction is dependant on the collision frequency multiplied by the fraction of collisions that are effective. Increasing the temperature increases the collision frequency as well as the fractions of collisions that are effective, so it’s definitely not that one. Hope this helped:)
Can u plz help me with my hw
Answer:
1) 4 x 25m = 100m
2) 0 because after 4 lengths, he's back at the starting block.
3) speed is distance over time so speed here is 100m/125s = 0.8m/s
4) ...
5) 100m / 1.25m/s = 80s
6.a) 100m / 0.5m/s = 200s
7.b) ... can't draw this now..
Numerical
What mass must be suspended from a steel wire 2m long and 1mm diameter to stretch it by 1mm
By young’s theory
Answer:
Thus, 4 kg mass must be suspended from a steel wire 2 m long and 1 mm diameter to stretch it by 1 mm.
Explanation:
In the pie chart below, which of the following represents the amount of Earth's surface covered by water?
A only
B only
B and C
D only
Answer:
A
Explanation:
As an object falls freely to the ground, what happens to its acceleration? increase decrease remains the same.
the primary factor in decreasing the kinetic energy of an object is to
Answer:
Decreasing the velocity
Explanation:
The primary factor in decreasing the kinetic energy of an object is to decrease the velocity of the object.
What is Kinetic energy?The kinetic energy of an object is the energy which it possesses due to the motion of the object. Kinetic energy is defined as the work which is needed to accelerate an object of a given mass from the state of rest to its stated velocity and direction. Gain of the energy during the acceleration of an object, the body maintains this kinetic energy unless its speed changes and the object accelerates.
The kinetic energy is directly proportional to the mass and the velocity of the object. The primary factor which is responsible for the decrease in the kinetic energy of an object is to decrease the velocity of the object.
Learn more about Kinetic energy here:
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Study the three pieces of evidence for the Big Bang in this activity carefully. What is common to all these pieces of observable evidence and why does this make them much more powerful than if they did not have this common feature?
Answer:
Explanation:
the measured abundances of elementsthe observed expansion of spacethe discovery of cosmic wave backgroundThe common observable evidence are:
the measured abundances of elementsthe expansion of spacethe cosmic wave backgroundWhat is big bang?The big bang is the theory which explains that how the universe began. It says that the universe began with just a single point. It went on expanding and stretched to grow as large as possible. It is still now expanding.
The big bang consist of fully dark matter, interstellar gases or dust. The big bang is increasing just because in universe there is abundant of hydrogen and helium.
The radiations come from the big bang. These rays are also called as cosmic wave. This big bang is still on it way of expanding more.
Thus, the observational evidence are the measured abundances of element, the expansion of space and the cosmic wave background.
Learn more about big bang.
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What does the universe look like on very large scales?
Answer:
it looks like dots and just black space on a large scale
Explanation:
on a large scale the universe especially our milky way looks small
hope this helps
What are 2 examples of Newton's second law in everyday life?
Answer:
kicking ball and throwing stone
Answer:
- Pushing a shopping cart
- Kicking a soccer ball
Explanation:
The second law states "It states that the time rate of change of the momentum of a body is equal in both magnitude and direction to the force imposed on it."
So two examples would be pushing / kicking anything (shopping cart or soccer ball for example) and riding a bicycle (bike = mass and you are the force)
Have a nice day!
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- Heather
PLEASE ANSWER NEED HELP!!!!!!!! PLEASE THE CORRECT ANSWER!!!!!!
Having good form is important when sitting but not when sleeping.
A.
True
B.
False
PLEASE NO LINKS
Answer:
B. false
Explanation:
Because good form is not going to mess up your sitting it might mess up the way you sleep Because you don't know if you going to hurt 8n the moring
A scientist fills a container with sea water. The container has dimensions 30 cm x 30 cm x 40 cm The density of sea water is 1020 kg/mº. Calculate the mass of the sea water in the container.
Answer:
30600kg
Explanation:
density=m/v make v subject of the formula
How to find velocity from acceleration time graph.
Answer:
We can only find the change in velocity by the area under the acceleration time graph by calculating the area under the curve to the given time. Then by the formula of the difference in the final and initial velocity you can find the final velocity of the object in the given time period.