Answer:
28.6 m/s
Explanation:
Using the equation for the range of a projectile,
R = U²sin2θ/g where U = initial speed of flaming pitch balls, θ = launch angle = 53° and g = acceleration due to gravity = 9.8 m/s²
Making U subject of the formula, we have
U = √(gR/sin2θ)
substituting the values of the variables into the equation given that R = 81.1 m, we have
U = √(9.8 m/s² × 81.1 m/sin2(53°))
U = √(794.78 m²/s²/sin106°)
U = √(794.78 m²/s²/0.9613)
U = √(826.78 m²/s²)
U = 28.75 m/s
U ≅ 28.6 m/s
Electronic flash units for camera contain a capacitor for storing the energy used to produce the flash. In one such unit, the flash lasts for 1675s with an average light power output of 2.70 x 105 W . (a) If the conversion of electric energy to light is 95% efficient ( the rest of the energy goes to thermal energy), how much energy must be stored in the capacitor for one flash
Answer:
420J
Explanation:
Power is the time rate of change in energy. Power is the ratio of energy to time. The S.I unit of power is in watts.
Given that the flash lasts for 1/675 s, power output is 2.7 * 10⁵ W. Hence:
Power = Energy / time
Substituting:
2.7 * 10⁵ W = Energy / (1/675)
Energy = 2.7 * 10⁵ W * 1/675 = 400J
Therefore the energy emitted as light is 400J.
Since the conversion of electric energy to light is 95% efficient, hence the energy stored as electrical energy is:
Energy(capacitor) = 5% of 400J + 400J = 0.05*400 + 400
Energy(capacitor) = 420J
A ball is dropped from rest out of a high window in a tall building for 5 seconds. Assuming the we ignore air resistance and assume upwards to be positive. A) What will be the final velocity of the ball B) What is the height of the building if it hits the ground after those 5 seconds. *
Answer:
I am not sure if this is the answer
(B) what is the height of the building if it hits the ground after those 5 seconds.
60.0 kg downhill skier is moving with a speed of 10.0 m/s as she starts her descent from a level plateau at 150.0 meters of height above the base of the slope below. The length of the slope is 650 meters. There is a frictional force of 70 N affecting the skier's motion while she coasts the entire descent without using her poles. Upon reaching the bottom she continues to coast to a stop. How much kinetic energy will she have at the bottom of the hill?
Answer:
She will have kinetic energy at the bottom of the hill=45700 J
Explanation:
We are given that
Mass, m=60 kg
Speed, v=10 m/s
Height, h=150 m
Length of slope, d=650 m
Frictional force, f=70 N
We have to find the kinetic energy she will have at the bottom of the hill.
Kinetic energy at the bottom of the hill
=Initial kinetic energy+ mgh-fd
Substitute the values
Kinetic energy at the bottom of the hill
=[tex]\frac{1}{2}(60)(10)^2+60\times 9.8\times 150-70\times 650[/tex]
=[tex]45700J[/tex]
Hence, she will have kinetic energy at the bottom of the hill=45700 J
Parallel Circuits:
A) are rarely used in the wiring in homes
B) always need more voltage than series circuits
C) will have positive charges flowing in one branch, negative charges in the other
D) provide more than one path fo current flow
Answer:
D.)
Explanation:
the current separates on each branch according to the resistance it experience.
Answer:D
Explanation:
Una esfera de aluminio de 250 g a una temperatura de 230 °C se introduce en 450 g de alcohol a una temperatura de 18 °C. Determine la temperatura de equilibrio del sistema. El calor específico del aluminio es 911 J kg-1 °C-1 y para el alcohol 2100 J kg-1 °C-1.
Answer:
La temperatura de equilibrio del sistema es de aproximadamente 59,17 °C
Explanation:
La masa de la esfera de aluminio, m₁ = 250 g
La temperatura inicial de la esfera de aluminio, T₁ = 230 °C
La capacidad calorífica específica del aluminio, c₁ = 911 J / (kg·°C)
La masa del alcohol, m₂ = 450 g
La temperatura inicial del alcohol, T₂ = 18 ° C
La capacidad calorífica específica del alcohol, c₂ = 2,100 J/(kg·°C)
Observamos que el punto de ebullición del alcohol ≈ 78,37°C
Sea 'T' la temperatura de equilibrio del sistema, obtenemos;
ΔQ₁ = ΔQ₂
ΔQ₁ = Calor transferido desde el aluminio = m₁ · c₁ · (T₁ - T)
ΔQ₂ = Calor transferido al alcohol = m₂ · c₂ · (T - T₂)
∴ m₁ · c₁ · (T₁ - T) = m₂ · c₂ · (T - T₂)
Por lo tanto, por sustitución, obtenemos
250 × 911 × (230 - T) = 450 × 2100 × (T - 18)
Usando una calculadora gráfica, tenemos;
T = 277570/4691 °C ≈ 59,17 °C
La temperatura de equilibrio del sistema, T ≈ 59.17 °C
Two forces of 8N and 10N CANNOT give a resultant of
a. 1 N
b. 2 N
c. 9 N
d. 18 N
Answer:
I believe it is D
forgive me if I'm wrong
5 points
1. A rubber-band-powered toy car is loaded by pushing it backward until
the rubber band inside is stretched tight. The child lets it go and the
rubber band turns the wheel, accelerating the car. The force that the
rubber band exerts on the axle is calle... *
O A. Applied Force
B. Electromagnetic Force
C. Gravitational Force
D. Elastic Force
Answer:
D. Elastic force
Explanation:
Force of elasticity
best explanation for why oceans have 2 different types of currents
Answer:
Hunubunununununununnunu
Which factor contributes the most to the process of water erosion?
A) evaporation
B) gravity
C) pressure
D) temperature
HELP
Answer:
Evaporation
Explanation:
Erosion is a natural process, but human activity can make it happen more quickly. Human activity altering the vegetation of an area is perhaps the biggest human factor contributing to erosion. Trees and plants hold soil in place.
Factor that contributes the most to the process of water erosion is Evaporation. The correct option is A.
What is evaporation?Evaporation is the phenomenon of converting the liquid into gas phase by the addition of heat energy.
Erosion is also a natural phenomenon. Trees and plants hold soil in place and prevents the soil erosion. Just like that, the water erosion happens when more than natural evaporation happens due to increased heat by various factors.
Thus, Evaporation contributes the most to the process of water erosion. The correct option is A.
After being struck by a bowling ball, a 1.8 kg bowling pin sliding to the right at 5.0 m/s collides head-on with another 1.8 kg bowling pin initially at rest. Find the final velocity of the second pin in the following situations: a) The first pin moves to the right after the collision at 0.8 m/s. Answer in units of m/s. 010 (part 2 of 2) 10.0 points b) The first pin stops moving when it hits the second pin. Answer in units of m/s
Answer:
a) v₂ = 4.2 m/s
b) v₂ = 5 m/s
Explanation:
a)
We will use the law of conservation of momentum here:
[tex]m_1u_1+m_2u_2=m_1v_1+m_2v_2[/tex]
where,
m₁ = m₂ = mass of bowling pin = 1.8 kg
u₁ = speed of first pin before collsion = 5 m/s
u₂ = speed of second pin before collsion = 0 m/s
v₁ = speed of first pin after collsion = 0.8 m/s
v₂ = speed of second after before collsion = ?
Therefore,
[tex](1.8\ kg)(5\ m/s)+(1.8\ kg)(0\ m/s)=(1.8\ kg)(0.8\ m/s)+(1.8\ kg)(v_2)\\v_2 = 5\ m/s - 0.8\ m/s[/tex]
v₂ = 4.2 m/s
b)
We will use the law of conservation of momentum here:
[tex]m_1u_1+m_2u_2=m_1v_1+m_2v_2[/tex]
where,
m₁ = m₂ = mass of bowling pin = 1.8 kg
u₁ = speed of first pin before collsion = 5 m/s
u₂ = speed of second pin before collsion = 0 m/s
v₁ = speed of first pin after collsion = 0 m/s
v₂ = speed of second after before collsion = ?
Therefore,
[tex](1.8\ kg)(5\ m/s)+(1.8\ kg)(0\ m/s)=(1.8\ kg)(0\ m/s)+(1.8\ kg)(v_2)[/tex]
v₂ = 5 m/s
Can any one help plz in the question ?
Yes, No, yes
mark me brainliestttt :)))
Answer:
yes
no
no
I think Chek the answer
In a warehouse, the workers sometimes slide boxes along the floor to move them. Two boxes were sliding toward each other and crashed. The crash caused both boxes to change speed. Based on the information in the diagram, which statement is correct? In your answer, explain what the forces were like and why the boxes changed speed.
Box 1 has more mass than Box 2.
Box 1 and Box 2 are the same mass.
Box 1 has less mass than Box 2
Answer:
The second one.
Explanation:
It caused both to change speed because they have both the same mass.
A TV has a power of 65 watts and an efficiency of 70 percent. How much
power is wasted as heat?
A. 19.5 W
B. 2.2 W
C. 0.9 W
D. 45.5 W
Power of TV = 65Watt
If Efficiency = 70%, then the percentage of energy wasted is 30%
So, the amount of energy getting wasted:
= 30/100 × 65
= 1950/100
= 195/10
= 19.5 W
An obect is placed 20cm from a convex mirror of focal length 12cm. where does the image form?
Answer:
7.5 cm behind the mirror
Explanation:
Applying,
Using the real is positive convection: All real distance from the mirror are positive
1/f = 1/v+1/u................. Equation 1
Where f = focal length of the mirror, v = image distance, u = object distance
From the question,
f = -12 cm, u = 20 cm
substitute these value into equation 1
1/(-12) = (1/20)+1/v
(-1/12)-(1/20) = 1/v
1/v = (-5-3)/60
1/v = -8/60
v = -60/8
v = -7.5 cm
Hence the image is formed 7.5 cm behind the mirror.
why doesn't the arrow fly forever
Because gravity pulls it down
expalin how waves energy and matter are related
What is the equation for speed?
Speed= time + distance
Speed= distance/time
Speed = time/distance
Speed = distance x time
Which term is defined as the ratio of the speed of light in a vacuum to the speed of light in the material it is passing through?
index of reflection
index of refraction
angle of incidence
angle of reflection
Answer:
The index of refraction
What is the index of refraction?
The index of refraction tells us how much slower or faster light travels from one medium to another.
What is a medium? ⇒ the substance that light passes throughThe formula to find the refractive index of a substance is the following:
[tex]n=\dfrac{c}{v}[/tex]
[tex]c[/tex] = the speed of light in a vacuum ([tex]3.00*10^8[/tex] m/s)[tex]v[/tex] = the speed of light in the mediumThis makes the index of refraction defined as the ratio of:
the speed of light in a vacuum the speed of light in the material it passes throughAnswer:
index of refraction
Explanation:
True or false
scientific research has now proven that atoms are composed of parts that are larger than protons neutrons and electrons
Answer:
False
Explanation:
parts that are smaller than protons neutrons and electrons
A tire has a tread pattern with a crevice every 2.20 cm. Each crevice makes a single vibration as the tire moves. What is the frequency of these vibrations if the car moves at 38.0 m/s
Answer:
17.27 Hz
Explanation:
Applying
v = λf................ Equation 1
Where v = speed of the car, λ = Distance between successive crevice, f = number of crevice moved in 1 seconds(Frequency of the vibration)
make f the subject of the equation
f = v/λ............. Equation 2
From the question,
Given: v = 38 m/s, λ = 2.2 m
Substitute these values into equation 2
f = 38/2.2
f = 17.27 Hz
I NEED THIS ASAP I WILL MARK YOU THE BRAINLIEST NO LINKS
Newton's second law states that force is equal to
weight times acceleration
weight divided by mass
mass times weight
mass times acceleration
Answer:
mass times acceleration
a rocket with an initial velocity of 20 m/s fires another engine that gives it an acceleration of 4 m/s2 over 10 seconds. How far did the rocket travel during this time?
Answer: 400 m
Explanation:
Vf= 20 + (4*10)
Vf= 60 [m/s]
x= (60^2 - 20^2) / (2*4)
x= 400 m
Sounds are made when objects ____ in air. What one word completes the sentence?
If anybody could help me it would be nice :) <333
Answer:
are crashing?
hope it's good hahah.
The correct answer is: "vibrate".
To find the correct word to complete the sentence, we need to know more about the sound wave.
What is sound wave?
Sound wave is a longitudinal wave i.e. the particles vibrate along the direction of propagation of wave.It requires a material medium to travel i.e. it can not travel in vacuum.How does sound wave produce?
Sound wave is produced due to variation of pressure in a medium. The high pressure region is compression region and low pressure region is rarefaction region.In case of an object, these pressure variations are produced by its vibration in a medium.Thus, we can conclude that sounds are made when objects vibrate in air.
Learn more about sound wave here:
https://brainly.com/question/1199084
#SPJ2
A bus travels to and from a school that is located 10 km to the west. What is the distance? What is the displacement?
20 km
Hope this helps Have a good day
Please help with this question
Answer:
the type of force is Unbalanced force;
As upward force is not equal to downward force.
How much energy is transferred in 10 seconds with a current of 13 amperes and a potential difference of 230 volts?
29900 J
Explanation:
Recall that
P = VI
= (230 volts)(13 A)
= 2990 watts
Also,
E = Pt
= (2990 watts)(10 s)
= 29900 J
What is the magnification when an object is placed at 2f from the pole of the convex mirror?
-2/ 3
-3/2
-1
-1/3
Answer:
Linear magnification = 1/3
Explanation:
Given:
Convex mirror
Object's distance from pole = 2f
Find:
Linear magnification
Computation:
Object distance, u = −2f
So,
1/v + 1/u = 1/f
1/v + 1/(-2f) = 1/f
1/v = 1/f + 1/2f
BY taking LCM
1/v = 3 / 2f
v = 2f / 3
Magnification, M = -v / u
So,
Magnification, M = (2f / 3) / 2f
Magnification, M = 2f / 6f
Magnification, M = 2 / 6
Linear magnification = 1/3
HELP PLEASE 20 ;OINTS
I'm walking 1.6m/s to 7-11 and it started to rain so I sped up to 2.7m/s in 1.2
seconds. What is my acceleration?
a=(vf-viyt
-0.92m/s2
O 01.1m/s2
0.92m/s2
1.1m/s2
1 points
Save A
Answer:
Explanation:
[tex]a = \frac{v_f-v_0}{t}[/tex] which is the final velocity minus the initial velocity in the numerator, and the change in time in the denominator. For us:
[tex]a=\frac{2.7-1.6}{1.2}[/tex] so
a = .92 m/s/s (NOT negative because you're speeding up)
Which of the following represent units of capacitance? You may choose more than one correct answer:
Ampere
coulomb/volt
coulomb/second
Farad
volt/coulomb
Answer:
Capacitance is a derived physical quantity measured in farad
Answer:
"Farad" is another term for the coulomb/volt measurement of capacitance, so both of those options are the correct answer. Amperes and coulomb/second are measurements of electric flow, in other words, how strong a current is.