Answer:
h = 0.46 m
Explanation:
According to the law of conservation of energy:
Potential Energy Lost by Roller Coaster = Kinetic Energy Gained by Roller Coaster
[tex]mgh = \frac{1}{2}mv^2\\\\2gh = v^2\\\\h = \frac{v^2}{2g}[/tex]
where,
h = height = ?
v = speed at bottom = 3 m/s
g = acceleration due to gravity = 9.81 m/s²
Therefore,
[tex]h = \frac{(3\ m/s)^2}{(2)(9.81\ m/s^2)}[/tex]
h = 0.46 m
20 POINTS:
Why does the initial hill of a roller coaster need to be steep?
Answer: A roller coaster does not have an engine to generate energy. The climb up the first hill is accomplished by a lift or cable that pulls the train up. This builds up a supply of potential energy that will be used to go down the hill as the train is pulled by gravity
Hope this helps! Good luck with future homework and exams!
A star produces energy by:
A: creating helium from hydrogen in its core.
B: reflecting energy from nearby stars.
C: absorbing and releasing the matter of other stars.
D: rotating quickly on its axis.
Here, the hydrogen atoms are combined to form a helium atom, and during this process of fusion, a significantly large amount of energy is released. Thus, stars produce a large amount of energy by forming helium from the combination of hydrogen in its core. Hence, the correct answer is option (C).
Answer:
A. Creating helium from hydrogen in its core.
Explanation:
Sacrificed my grade for points I hope it helps
A nucleus with mass number 229 emits a 3.443 MeV alpha particle. Calculate the disintegration energy Q for this process, taking the recoil energy of the residual nucleus into account.
Answer:
3.504 MeV
Explanation:
Given that;[tex]\frac{A}{Z} X ---->\frac{A-4}{Z-2} Y +\alpha + Q[/tex]
Also;
[tex]Q= KE_{\alpha } (M_{Y} + M_{\alpha } /M_{Y[/tex])
Mass number of X = 229
Mass number of Y = 225
Mass number of alpha particles = 4
Kinetic energy of alpha particles = 3.443 MeV
Q = 3.443 MeV (225 + 4/225)
Q= 3.504 MeV
which of the following is a vector physical quantity
a. speed
b. energy
c. mass
d. displacement
Answer:
D. displacement
Explanation:
Vector quantities have both magnitude and direction.
Scalar quantities have only magnitude.
Usain bolt ran the 200m race within 19.19 seconds. Calculate the speed of Usain bolt during the race
Answer: [tex]10.42\ m/s[/tex]
Explanation:
Given
Usain Bolt ran the race with a length [tex]200\ m[/tex]
Time is taken to complete it [tex]t=19.19\ s[/tex]
We know, [tex]\text{Distance}=\text{speed}\times \text{time}[/tex]
Insert the values
[tex]\Rightarrow 200=v\times 19.19\\\\\Rightarrow v=\dfrac{200}{19.19}\\\\\Rightarrow v=10.42\ m/s[/tex]
So, the speed of Usain Bolt is [tex]10.42\ m/s[/tex]
A beam of light hits a mirror at an angel of 35 degrees. What is the angel that it bounces off at?
a. 55 degrees
b. 35 degrees
c. 90 degrees
Answer:
c
Explanation:
light refraction is a right angle
Which of the following statements explains how total time spent in the air is affected as a projectile's angle of launch is increased from 25 degrees to 50 degrees?
Answer:
Therefore letter C is the correct answer.
Explanation:
In a projectile motion the total time in the air can be calculated using the following equation:
We analyze the y-component motion.
[tex]v_{fy}=v_{iy}-gt[/tex]
When the final velocity (v(f)) is equal to zero we calculate the upward time and multiplying it by 2 we find the total time in the air. So we will have:
[tex]t_{tot}=2\frac{v_{iy}}{g}[/tex]
[tex]t_{tot}=2\frac{v_{i}sin(\theta)}{g}[/tex]
We can see that the total time is directly proportional to the angle, then when θ increase t increase.
Therefore letter C is the correct answer.
I hope it helps you!
11. In a new science fiction movie an enemy spaceship explodes. Will an observer on a nearby
moon hear the explosion, see the explosion, or both? Explain
Answer:
Sound is transmitted by longitudinal waves thru air - the observer cannot hear the explosion because no air is present between the moon and the ship
Light is transmitted by electromagnetic waves so the light from the explosion can travel between the moon and the observer.
A 4kg and 5kg bodies moving on a frictionless horizontal surface at a velocity of ( -6i )m/s and ( +3 )m/s respectively. Collide a head on elastic collision. What is the velocity ( magnitude and direction) of the each body after collision?
Answer:
4 kg → +4 m/s
5 kg → -5 m/s
Explanation:
The law of conservation of momentum states that:
m₁v₁ + m₂v₂ = m₁v₁' + m₂v₂'left side → velocities before collisionright side → velocities after collisionYou'll notice that we have two missing variables: v₁' & v₂'. Assuming this is a perfectly elastic collision, we can use the conservation of kinetic energy to set the initial and final velocities of the individual bodies equal to each other.
v₁ + v₁' = v₂ + v₂'Let's substitute all known variables into the first equation.
(4)(-6) + (5)(3) = (4)v₁' + (5)v₂' -24 + 15 = 4v₁' + 5v₂' -9 = 4v₁' + 5v₂'Let's substitute the known variables into the second equation.
(-6) + v₁' = (3) + v₂' -9 = -v₁' + v₂' 9 = v₁' - v₂'Now we have a system of equations where we can solve for v₁ and v₂.
-9 = 4v₁' + 5v₂' 9 = v₁' - v₂'Use the elimination method and multiply the bottom equation by -4.
-9 = 4v₁' + 5v₂' -36 = -4v₁' + 4v₂'Add the equations together.
-45 = 9v₂'-5 = v₂'The final velocity of the second body (5 kg) is -5 m/s. Substitute this value into one of the equations in the system to find v₁.
9 = v₁' - v₂'9 = v₁' - (-5) 9 = v₁' + 5 4 = v₁'The final velocity of the first body (4 kg) is 4 m/s.
We can verify our answer by making sure that the law of conservation of momentum is followed.
m₁v₁ + m₂v₂ = m₁v₁' + m₂v₂' (4)(-6) + (5)(3) = (4)(4) + (5)(-5)-24 + 15 = 16 - 25 -9 = -9The combined momentum of the bodies before the collision is equal to the combined momentum of the bodies after the collision. [✓]
A 330.-ohm resistor is connected to a 5.00-volt battery. What is the current through the resistor?
Answer:
From Ohms Law
V=IR
V=5volts
R=33.0hms
I=V/R
I= 5/330
=0.0152A
The current flowing through the cross-section of the resistor is 0.0152A.
Given the data in the question;
Resistance; [tex]R = 330ohm[/tex]Voltage; [tex]V = 5.00V[/tex]Current; [tex]I = \ ?[/tex]Ohm's lawOhm's law states that "the current flowing through the cross-section of a conductor is directly proportional to the voltage across it".
It is expressed as;
[tex]V = IR[/tex]
Where V is voltage, I is current and R is the Resistance.
To determine the current flowing through the resistor, we substitute our given values into the expression above.
[tex]V = IR\\\\I = \frac{V}{R}\\ \\I = \frac{5.00V}{330\ Ohm} \\\\I = 0.0152A[/tex]
Therefore, the current flowing through the cross-section of the resistor is 0.0152A.
Learn more about Electric current here: https://brainly.com/question/2264542
ik its a lot but can u help
Answer:
your correct ans is D.
object float in liquid when its density is less than liquid and sinks when its density is more than liquid..
stay safe healthy and happy.Does a feather fall as fast as a rock in a vacuum? If so why?
Answer:
No.
Explanation:
A feather is less dense and thus less force exerted while a rock is very dense thus exerting more force .
A forensics investigator discharged an assault rifle-replica such that the bullet fired at an angle of 30 (degrees) off the horizontal with an initial velocity
of 28
m/s northwest. What is the maximum height the bullet will reach?
O 14 m/s
10 m
O 30 km
O 0.4351 seconds
Answer:
Initial y-component of speed
Vy = 28 * sin 30 = 14 m/sec vertically
1/2 m Vy^2 = 2 m g h conservation of energy of y-component
h = Vy^2 / (2 * g) = 14^2 / (2 * 9.8) = 10 m
A force of 20N displaces an object to 5m in 10s. Calculate the power.
Answer:
hope it helps you see the attachment for further information
In a physics lab, Ray Zuvlite arranges two mirrors with a right angle orientation as shown. Ray then directs a laser line at one of the mirrors. The light reflects off both mirrors as shown. If angle A is 25°, determine the what is the angle measure of angles B, C, and D?
Answer:
B = 25°
C = 65°
D = 25°
Explanation:
The given parameters are;
The orientation of the two mirrors = At right angle to each other
The laser light is directed at one of the mirror
The measure of angle, A = 25°
The measures of angle B, C, and D are found as follows;
We have;
∠A = ∠B = 25°, by angle of incidence equals angle of reflection
∠B = 25°
∠B + ∠C = 90° by sum of the acute angles of a right triangle
25° + ∠C = 90°
∴ ∠C = 90° - 25° = 65°
∠C = 65°
∠E = ∠C = 65° by angle of incidence equals angle of reflection
∴ ∠E = 65°
Line 'L' is perpendicular to the second mirror, therefore, the angle between line 'L' and the second mirror = 90° = ∠E + ∠D
∠E + ∠D = 90°, by angle sum property
Therefore;
65° + ∠D = 90°
∴ ∠D = 90° - 65° = 25°
∠D = 25°
A beam strikes an irregular mirror and is reflected as shown below. The angle formed by the incoming beam and the reflected beam is 10 degrees. What is the angle of the mirror's surface (measured against vertical) at the location where the beam strikes the mirror?
A. The mirror's surface is angled 5 degrees upward where the laser strikes it.
B. The mirror's surface is angled 5 degrees downward where the laser strikes it.
C. The mirror's surface is angled 10 degrees upward where the laser strikes it.
D. The mirror's surface is angled 10 degrees downward where the laser strikes it.
Answer:
the correct answer is B
Explanation:
The law of reflection states that the angles of incidence and reflection on a surface are the same, the two rays and the normal are in the same part of the surface.
In this exercise indicate that the angle between the incident and reflected ray is 10, therefore the angle with respect to the normal that is a vertical line at the point of contact of the ray must be 5
Consequently the correct answer is B
What would the axes be labelled on a graph that allows you to calculate VELOCITY?
hii can someone pls help me??
F = ma
F = 8.5 × 6
F = 51 N
................
If a roller-coaster car has 40,000 J of gravitational potential energy when at rest on the top of a hill, how much kinetic energy does it have when it is ½ of the way down the hill?
=============================================
Work Shown:
PE = potential energy
KE = kinetic energy
m = mass
g = acceleration of gravity
h = height of the object
PE = m*g*h = 40,000 joules
---------
If the car is halfway down the hill, then that means the height of the car is h/2 instead of h
We can then say:
m*g*(h/2) = (m*g*h)/2 = (40,000)/2 = 20,000 J
is the amount of potential energy at this location. The amount of kinetic energy must be the remaining amount that adds to this, to get 40,000 J again.
Put another way: The 40,000 J of PE to start off with, when KE = 0, means we have a total energy of 40,000 J
---------
So,
PE+KE = total energy
PE+KE = 40,000 J
20,000 J + KE = 40,000 J
KE = (40,000 J) - (20,000 J)
KE = 20,000 J when the car is halfway down the hill.
On what factors does critical velocity depend on
Explanation:
The critical velocity is that velocity of liquid flow, up to which its flow is streamlined (laminar)& above which its flow becomes turbulent. It's denoted by Vc & it depends upon: Coefficient of viscosity of liquid (η) Density of liquid. Radius of the tube.
The length of a planet's day is determined by it's
Answer: "People will say the length of a day is determined by just the rotation rate of a planet, but that isn’t entirely true. The orbit around its sun also factors in. What we define as a day is the time between when the Sun is highest in the sky until the next time the Sun is at the highest point in the sky. This isn’t just the time it takes the Earth to rotate once on its axis, though. This is because, as the Earth is rotating, it’s also moving relative to the Sun"
Which term BEST describes energy
stored in batteries and food?
potential energy
kinetic energy
heat energy
chemical energy
Two people are sitting on wheeled chairs 1 metre apart. Person A is holding a 2kg ball. Person A throws the ball to Person. What happens to person A? Explain.
a.) their chair stays still
b.) chair rolls backwards
c.) chair rolls forwards
Answer:
B - Person A's chair rolls backwards.
Explanation:
This can be seen simply through the Conservation of Momentum. When the ball is thrown to be, the ball's momentum(+m) is transfererd to B, so B's chair moves forward(think about it - it makes sense, doesn't it?), meaning A's chair moves backwards.
So, B.
EXTRA TIP: Try drawing a diagram to help you!
why should we measure accurately
Answer:
To obtain fair results
Explanation:
if we don't measure the results might give unfair results
Answer:
Accurate measurement s r important bcz precise amounts r required for reaçtiøñ#s tø take place før a recipe tø turn out ãnd tø keep correct records of A measurement
uR ANSWER HOPE IT HELPS YOU...What is meant by denser medium?
Explanation:
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Einstein's theory of general relativity is currently the best explanation of gravity.Why has this theory not been replaced with a new one
Answer:
Option C, It still explains the experimental evidence pertaining to gravity
Explanation:
Please find the attachment
Answer:
A.) It will remain the best explanation, because no one has come up with a better one yet
Explanation:
Why x rays have different properties from light even though both originate from orbital transition of electrons in excited atoms?
Answer:
he difference between X-rays and visible radiation is in the energy of each foton.
Explanation:
Visible light and X-rays are electromagnetism waves with the same origin betray the atomic, but the energy of transioin wings is different,
E = h (v_f - v₀)
With this equation we see that the energy is proportional to the difference between the atomic levels where the ranscion occurs, the X-rays the transition involves deep levels n = 1 or 2 for which the energy of the emitted photon is very high.
The visible radiation the transition is between levels closer so that the emitted light has a lower frequency and is in the range of the visibly
Consequently, the difference between X-rays and visible radiation is in the energy of each foton.
A plane travels at an average speed of 600 kilometers per hour. How long
does it take the plane to travel 120 kilometers?
Answer:
12 mins
Explanation:
120km/600km = 1/5 or .2
60mins*0.2 = 12 mins
Problem 6. A negatively charged particle is placed in a uniform electric field directed
from South to North. In which direction will the particle move after it is released?
A) West
B) East
C) South
D) North
E) North-West
po
UP
A
B
Meeting na
D
Activate!
Go to Setting
C) South
As we know that, north is considered as negative, and south as positive. Now, the charge on particle is negative; so, when we will release it, it will move towards the south.
In the scenario where the negatively charged particle is placed in a uniform electric field, the direction will be C. South.
What is an electric field?It should be noted that an electric field simply means the physical field which surrounds electrically charged particles.
Since the negatively charged particle is placed in a uniform electric field directed from South to North, the direction that the particle move after it is released is South.
Learn more about electric field on:
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plsss helpp i really need this now thank u ❤️
Answer:
10.
parabolic
11.
Entirely horizontal
12.
45°