Answer:
Correct choice: b 4H
Explanation:
Conservation of the mechanical energy
The mechanical energy is the sum of the gravitational potential energy GPE (U) and the kinetic energy KE (K):
E = U + K
The GPE is calculated as:
U = mgh
And the kinetic energy is:
[tex]\displaystyle K=\frac{1}{2}mv^2[/tex]
Where:
m = mass of the object
g = gravitational acceleration
h = height of the object
v = speed at which the object moves
When the snowball is dropped from a height H, it has zero speed and therefore zero kinetic energy, thus the mechanical energy is:
[tex]U_1 = mgH[/tex]
When the snowball reaches the ground, the height is zero and the GPE is also zero, thus the mechanical energy is:
[tex]\displaystyle U_2=\frac{1}{2}mv^2[/tex]
Since the energy is conserved, U1=U2
[tex]\displaystyle mgH=\frac{1}{2}mv^2 \qquad\qquad [1][/tex]
For the speed to be double, we need to drop the snowball from a height H', and:
[tex]\displaystyle mgH'=\frac{1}{2}m(2v)^2[/tex]
Operating:
[tex]\displaystyle mgH'=4\frac{1}{2}m(v)^2 \qquad\qquad [2][/tex]
Dividing [2] by [1]
[tex]\displaystyle \frac{mgH'}{mgH}=\frac{4\frac{1}{2}m(v)^2}{\frac{1}{2}m(v)^2}[/tex]
Simplifying:
[tex]\displaystyle \frac{H'}{H}=4[/tex]
Thus:
H' = 4H
Correct choice: b 4H
what is the two kinds of solids in amorphous
Solids can be classified into two types: crystalline and amorphous. Crystalline solids are the most common type of solid. They are characterized by a regular crystalline organization of atoms that confer a long-range order. Amorphous, or non-crystalline, solids lack this long-range order.
If you are sitting in a bus that is traveling along a straight, level road at 100 km/hr., you are traveling at 100 km/hr too. (a) If you hold an apple over your head, how fast is it moving relative to the road? (b) Relative to you? (c) If you drop the apple, does it still have the same horizontal motion? Explain.
What Law is it?
(a) The velocity of the apple with respect to the road is 100 km/h.
(b) The velocity of the apple with respect to you is 0 km/h.
(c) If you drop the apple the horizontal velocity will not change due to law of conservation of linear momentum.
What is the relative velocity of the apple?
The relative velocity of the apple placed over your with respect to the road is calculated as follows;
Velocity of the apple = 100 km/h
Velocity of the road = 0 km/h
Va/r = 100 km/h - 0 km/h
Va/r = 100 km/h
The velocity of the apple relative to you is calculated as follows;
your velocity = 100 km/h
velocity of the apple = 100 km/h
Va/y = 100 km/h - 100 km/h
va/y = 0 km/h
If you drop the apple, the horizontal velocity will remain the same, because gravity does not affect horizontal motion.
The law is law of conservation of linear momentum.
Learn more about relative velocity here: https://brainly.com/question/17228388
#SPJ1
Help me pretty please with a cherry on top!!
Answer:
A. im not for sure hope it helps
Explanation:
What happens to the pressure as air rises from the ground into the atmosphere?
Does it increase or decrease?
Answer:
please try brainlist answer
As the atmosphere expands the further you get from the Earth's surface, it becomes less dense and air pressure decreases. As you increase altitude (distance from Earth's surface) in an airplane, air pressure changes
कृपया ब्रेनलिस्ट का उत्तर केवल 1more उत्तर देने का प्रयास करें।
How do I calculate how many meters are in 7.2 light years?
The exact question is:
Calculate in meters the distance between a galaxy and the Earth if the distance is equal to 7.2 light years.
Answer:
68.2 Quadrillion meters
Explanation:
A lightyear is the distance that light travels in one year.
Speed of light is [tex]3*10^8\ m/s[/tex]
So light covers 300,000,000 meters in one second.
One year has 31536000 seconds so , light covers
[tex]9.461*10^{15}\ meters\ in\ one\ year[/tex]
so 7.2 light years is
[tex]7.2*(9.461*10^{15})\\6.82*10^{16}[/tex]
so 7.2 light years is
6.82 x 10^(16) meters or
68.2 Quadrillion meters
Electric power is to be generated by installing a hydraulic turbine-generator at a site 70 m below the free surface of a large water reservoir that can supply water at a rate of 1500 kg/s steadily. If the mechanical power output of the turbine is 800 kW and the electric power generation is 750 kW, determine the turbine efficiency and the combined turbine–generator efficiency of this plant. Neglect losses in the pipes.
Answer:
[tex]\eta_{turbine} = 0.777 = 77.7\%[/tex]
[tex]\eta_{combined} = 0.728 = 72.8\%[/tex]
Explanation:
First we calculate the power input to the turbine. The input power will be equal to the potential energy of water per unit time:
Input Power = [tex]P_{in} = \frac{Work}{Time} = \frac{Potential\ Energy\ of\ Water}{t} \\P_{in} = \frac{(mass)(g)(height)}{Time} = (mass flow rate)(g)(height)\\\\P_{in} = (1500\ kg/s)(9.81\ m/s^2)(70\ m)\\P_{in} = 1.03\ x\ 10^6\ W = 1030\ KW[/tex]
Now, for turbine efficiency:
[tex]\eta_{turbine} = \frac{Mechanical\ Power\ Out}{P_{in}}\\\\\eta_{turbine} = \frac{800\ KW}{1030\ KW}\\\\\eta_{turbine} = 0.777 = 77.7\%[/tex]
for generator efficiency:
[tex]\eta_{generator} = \frac{Power\ Generation}{Mechanical\ Power\ Out}\\\\ \eta_{generator} = \frac{750\ KW}{800\ KW}\\\\\eta_{turbine} = 0.9375 = 93.75\%[/tex]
Now, for combined efficiency:
[tex]\eta_{combined} = \eta_{turbine}\ \eta_{generator}\\\\\eta_{combined} = (0.777)(0.937)\\\eta_{combined} = 0.728 = 72.8\%[/tex]
A 10kg ball has a momentum of 40 kg.m/s. What is the ball’s speed.
Show the work and equations.
Answer:
4 m/sExplanation:
The speed of the ball can be found by using the formula
[tex]s= \frac{p}{m} \\ [/tex]
p is the momentum
m is the mass
From the question we have
[tex]v = \frac{40}{10} = 4 \\ [/tex]
We have the final answer as
4 m/sHope this helps you
An object weighing 49 N is pushed across a floor by a force of 12 N. What is the acceleration of the object?
Answer:
Explanation:
Given parameters:
Weight of object = 49N
Force applied = 12N
Unknown:
Acceleration of object = ?
Solution:
The acceleration of the object is found by dividing the force by the weight;
Acceleration = [tex]\frac{12}{49}[/tex] = 0.25m/s²
Should the resistance of an ammeter low or high ?give reason
Answer:
The resistance of an ammeter should be low. This is because an ammeter is connected in series with the circuit for the measurement of electric current. In case, its resistance is high, then some amount of current may lost in heating it leading to the inaccurate reading. An ideal ammeter is one which has zero resistance.
A pulse with a height of 20 cm and a length of 30 cm travels with a speed of 400 cm/s through a spring that has been stretched so it is 800 cm long. If we want to send another pulse through the spring that will have a different speed, which of the bolded words should we change? List all that will change the speed of the wave.
Answer:
To send a pulse of different speed, change the tension or stretch on the spring
Explanation:
A pulse is a single disturbance of a particle is a medium. The pulse has an amplitude or and a pulse length in the medium. The speed of the pulse is dependent on the amount of strain or tension ( stretch) applied to the medium. The speed also determines the length of the pulse but is unaffected by the or amplitude of the pulse.
Write 2 laws of reflection of light
Answer:
Answer⤵i)The first law of reflection states that the incident ray, the reflected ray, and the normal to the surface of the mirror, all lie in the same plane. ii)The second law of reflection states that the angle of reflection is equal to the angle of incidence. Both angles are measured with respect to the normal to the mirror.41. What effects the efficiency of a pulley?
a. the type of rope or cable
b. the way the wheel turns
c. the length of the rope
d. how big the wheel is
e. only a and be
f. all of the above
Answer:
e. only a and b
HELP ASAP !
Which of the following situations would result in no work done by the force indicated?
a
The object undergoes only a slight displacement while the force is acting on it.
b
The force is perpendicular to the displacement of the object.
c
The force is not completely parallel to the displacement of the object
d
All of the above result in no work done by the force indicated.
Answer:
b The force is perpendicular to the displacement of the object.
Explanation:
Work is done when a force is applied on a body causing it to move in a particular direction.
Work done = Force x displacement
For work to be done, a force must applied on a body to move it through a specific distance in direction.
When force is perpendicular to the displacement of the object, the component vector resolution is 0 and the work done is 0.
1. Which statement best describes the motion of the scooter? *
A. The scooter is moving at a constant velocity.
B. The scooter is traveling up hill.
C. The scooter is speeding up at a constant rate.
D. The scooter’s motion cannot be described from a position graph.
2. What is the velocity of the scooter? *
A. 50 m/s
B. 10 m/s
C. 1.0 m/s
D. 0.0 m/s
E. Cannot answer velocity questions using a position graph
Answer:
HI
Explanation:
its E
A supply plane drops a package to the ground for stranded campers below. After falling for 8.14 seconds, the package will have a downward velocity of 80.79 m/s. How high was the plane when it dropped the package?
Answer:
333 m
Explanation:
The following data were obtained from the question:
Initial velocity (u) = 0 m/s.
Time (t) = 8.14 s.
Final velocity (v) = 80.79 m/s.
Acceleration due to gravity (g) = 9.8 m/s²
Height (h) =?
v² = u² + 2gh
80.79² = 0 + (2 × 9.8 × h)
6527.0241 = 0 + 19.6h
6527.0241 = 19.6h
Divide both side by 19.6
h = 6527.0241 / 19.6
h = 333 m
Thus, the plane was at a height of 333 m when the package was dropped.
Which type of air mass forms over the ocean near the equator?
A
moist and warm
B
moist and cool
C
dry and warm
D
dry and cool
Answer:
a
Explanation:
What is the density of an object with a mass of 20 grams and a volume of 5 cm?
Answer:
4
Explanation:
Divide mass(m) by volume(v), you get density(D)
m/v=D
20/5=4
Which of the following is most accurate statement about both light and sound wave
Which pair of concurrent forces could produce a resultant force having a magnitude of 10. Newtons?
The pair of concurrent forces will be of 5 N to make the magnitude of net force as 10 N.
Given data:
The magnitude of resultant force is, [tex]F_{net}=10 \;\rm N[/tex].
The given problem is based on the concept of concurrent forces which says that, If the forces applied to a body are such that their lines of action meet at a single point, then they are called concurrent forces.
Now to obtain the value of concurrent forces, let us consider the forces F and F' to be acting along a linear direction. Such that the net force is given as,
[tex]F_{net}=F+F'[/tex]
Then for 10 N of net force, the pair of concurrent force is,
[tex]10=F+F'\\\\10=5+5\\\\10=10[/tex]
Thus, we conclude that the pair of concurrent forces will be of 5 N to make the magnitude of net force as 10 N.
Learn more about the concurrent force here:
https://brainly.com/question/2411525
Help please!!!
if superman at 90kg jumps a 40m building in a single bound how much work does superman perform
Answer:
5 years worth of work (aka all of the homework i currently have)
A 20 kg mass is hanging on one side of a pulley and a 5 kg mass is hanging on the other. Determine the acceleration of each mass.
Answer:
i believe it's 7
Explanation:
7. A 1000-kg car comes to a stop without skidding. The car's brakes do 50,000 J of work
to stop the car. Which of the following was the car's velocity when the brakes were
initially applied?
Answer:
10 m/s
Explanation:
Which is true of the greenhouse effect?
A. It is purely a manmade phenomenon.
B. it does not involve carbon dioxide.
C. It causes cooling of Earth's atmosphere.
C. it traps thermal energy from the Sun.
Answer:
c is correct option thanks to brainly
it is very important to use _______ in your calculations
a: si units of measurement
b: alternative units of measurement
c : units of length and width
d: derived units
Answer:
snoemw
Explanation:
If you add an additional neutron to an atomwhat do you create?
Answer:
However, if you add a thousand neutrons, you will be creating one super-radioactive atom. Neutrons play a major role in the mass and radioactive properties of atoms. You may have read the page on isotopes. Isotopes are created when you change the normal number of neutrons in an atom.
Explanation:
The neutron is a subatomic particle, symbol n or n⁰, which has a neutral (not positive or negative) charge and a mass slightly greater than that of a proton. Protons and neutrons constitute the nuclei of atoms. Since protons and neutrons behave similarly within the nucleus, and each has a mass of approximately one atomic mass unit, they are both referred to as nucleons. Their properties and interactions are described by nuclear physics.
If a refrigerator draws about 0.5 amps when plugged into a 120 V wall outlet how much power (watts) does it use?
Answer:60 W
Explanation:
Which of the following is the keyboard shortcut for saving a document?
O Control V
O Control S
O Control A
O Control E
Answer:Control S, Command S on MAC=Save
Plz di all plz i will give brainest and thanks to best answer do it right
A car with a mass of 1600 kg is towing a trailer with a mass of 420 kg. The car
provides a forward thrust of 3300 N. What is the acceleration of the trailer?
Answer:
1.63366
Explanation:
I got this answer from calculator soups physics calculators. I really recommend their website for formulas.
A rat runs 2m right, turns around and runs 3m left. Then goes 2m right. What is its displacement?
A. 1m right
B. 1m left
C. 7m
D. 7m left
Answer:
Explanation:
I think this answer would be 1m to the left.
