Answer:
number 4
Explanation:
The reflection of light happens when the light bounces off the reflecting surface. That is described by the last (bottom) schematics.
Therefore, select answer number 4.
what volume of alcohol will have the same mass as 4.2m^3 of petrol? (density of alcohol 0.4kg/m^3 and petrol is 0.3kg/m^3)
Answer:
3.15m³
Explanation:
To solve this problem, let us first find the mass of the petrol from the given dimension.
Mass = density x volume
Volume of petrol = 4.2m³
Density of petrol = 0.3kgm⁻³
Mass of petrol = 4.2 x 0.3 = 1.26kg
So;
We can now find the volume of the alcohol
Volume of alcohol = [tex]\frac{mass}{density}[/tex]
Mass of alcohol = 1.26kg
Density of alcohol = 0.4kgm⁻³
Volume of alcohol = [tex]\frac{1.26}{0.4}[/tex] = 3.15m³
A cell of e.M.F 1.5v and internal resistance 2.5ohm is connected in series with an ammeter of resistance 0.5ohm. Calculate the current in the circuit.
Given :
A cell of e.m.f 1.5 V and internal resistance 2.5 ohm is connected in series with an ammeter of resistance 0.5 ohm.
To Find :
The current in the circuit.
Solution :
We know, resistance of the ammeter is in series with the circuit.
So, total resistance is :
R = 2.5 + 0.5 ohm
R = 3 ohm
Also, e.m.f applied is 1.5 V .
Now, by ohm's law :
[tex]I = \dfrac{V}{R}\\\\I = \dfrac{1.5}{3}\\\\I = 0.5 \ A[/tex]
Therefore, the current in the circuit is 0.5 A.
A ball is thrown with 50J of kinetic energy, it hits a target which moves with 30J of kinetic energy, how much energy goes to the thermal store of the surroundings?
Answer:
The energy that will go will for thermal store of the surroundings is 20 J.
Explanation:
Given;
kinetic of the thrown ball, K.E₁ = 50 J
kinetic energy used to move the target, K.E₂ = 30 J
The excess energy that will go will for thermal store of the surroundings;
ΔK.E = K.E₁ - K.E₂
ΔK.E = 50J - 30J
ΔK.E = 20 J
Therefore, the energy that will go will for thermal store of the surroundings is 20 J.
A vector
of magnitude 5 units and another vector ū of magnitude 3 units point in directions
differing by 60°. Find out (a) the scalar product of the two vectors and (b) the vector product of the two vectors
Answer:
7.5 units
13 units
Explanation:
[tex]|v|=5\ \text{units}[/tex]
[tex]|u|=3\ \text{units}[/tex]
[tex]\theta[/tex] = Angle between the vectors = [tex]60^{\circ}[/tex]
Scalar product is given by
[tex]u\cdot v=|u||v|\cos\theta\\ =3\cdot 5\cdot \cos60^{\circ}\\ =7.5\ \text{units}[/tex]
The scalar product of the vectors is 7.5 units.
Vector product is given by
[tex]u\times v=|u||v|\sin\theta\\ =3\times 5\sin60^{\circ}\\ =13\ \text{units}[/tex]
The vector product of the vectors is 13 units.
how to make measurements of length, volume and time?
Answer:
The volume of a regular object can be calculated by multiplying its length by its width by its height. Since each of those is a linear measurement, we say that units of volume are derived from units of length.
Explanation:
Answer:
length×Width×Height
Explanation:
Length×Width×Height is the formula for volume
Please what is the work done by a man who is pulling a box of 45kg of mass by means of rope which makes angle of 45 degrees ?
Answer:
No work is done since no distance is given
Explanation:
Since no distance is given, the force is not doing any work
No work is done by the man since we do not know the distance or displacement.
Work is only said to be done when the force applied on an object moves it through a particular distance.
Work done = Force x distance.
Since no distance is given in this problem, we can as well assume that the force applied is doing no work on the object.
what are the importance of gravitation
Answer:
Gravity is very important to us. We could not live on Earth without it. The sun's gravity keeps Earth in orbit around it, keeping us at a comfortable distance to enjoy the sun's light and warmth. It holds down our atmosphere and the air we need to breathe.
Answer:
Newton's universal law of gravitation explains the attractive force between any two objects which have mass.It explains how we are able to stand on earth, why a body thrown up falls to the ground, why planets revolve around the sun and why the moon revolves around the earth, and so on.This law says that as the distance between two objects increases their force of attraction decreases. This explains why we are not pulled towards a distant star even though it is more massive than the Earth.This law leads to the derivation of an expresion for the acceleration due to gravity...With the help of gravitation, we can understand the force experience by various planets , stars etc. with each other.This law makes us understand why the planets revolve around the sun and why satellite revolve around the planets.Gravitation explains us how the planets are held by the sun and why don't they fall on it.It can also explain how tides are formed on earth. (Tides are due to the gravitational forces of the sun and the moon).Example:
Astronauts reach a distant planet and find it takes eight times as much force to lift objects there than it does on Earth. What is the acceleration due to gravity on this planet?
On this planet the force of gravity is eight times larger. Since the masses of objects are a fundamental property of those objects, they cannot change, that means the value of g must be eight times larger as well:
[tex]8F_{grav}=m(8g)8F[/tex]
[tex]=m(8g)[/tex]
The value of g on Earth is 9.8 m/s2, so 8 × 9.8 m/s2 = 78.4 m/s2.
How would I solve this? It's Newton's 2nd law
Answer:
5.65 m/s²
Explanation:
We'll begin by calculating the mass of PJ when in San Diego (i.e Earth). This can be obtained as follow:
Weight of PJ on Earth (Wₑ) = 545 N
Acceleration due to gravity (g) on Earth (gₑ) = 10 m/s²
Mass of PJ on Earth (mₑ) =.?
Wₑ = mₑ × gₑ
545 = mₑ × 10
Divide both side by 10
mₑ = 545 / 10
mₑ = 54.5 Kg
Thus, the mass of PJ on San Diego (i.e Earth) is 54.5 Kg
Finally, we shall determine the acceleration due to gravity of planet Koja. This can be obtained as follow:
Weight of PJ on Koja (Wₖ) = 308 N
Mass of PJ on Koja (mₖ) = mass of PJ on Earth (mₑ) because mass is constant irrespective of location.
Mass of PJ on Earth (mₑ) = 54.5 Kg
Mass of PJ on Koja (mₖ) = 54.5 Kg
Acceleration due to gravity of on Koja (gₖ) =?
Wₖ = mₖ × gₖ
308 = 54.5 × gₖ
Divide both side by 54.5
gₖ = 308 / 54.5
gₖ = 5.65 m/s²
Thus, the acceleration due to gravity on planet Koja is 5.65 m/s²
3. A bee flies forward at 4.9 for 33 s, lands on a flower and stays there for 7s, then flies back along its previous route at 1.9 for 39 s. What is the average speed of the bee
during the entire time?
O 1.701
O 3.001
O 4.466
O 3.801
None of these is correct.
Answer:
None of these is correct.
Explanation:
The average speed can be derived from the sum of the total distance traveled and the total time taken.
Total distance = 4.9 + 1.9 = 6.8
Total time taken = 33 + 39 = 72
So;
Average speed = [tex]\frac{total distance}{total time}[/tex] = [tex]\frac{6.8}{72}[/tex] = 0.014
None of the answer choices given is correct.
An aeroplane of mass 30000kg produced a force of 20kN to get it to accelerate to 50m/s so it could take off. Calculate the amount of time it was accelerating for
Will mark branliest! Need working out aswell!
Answer:
[tex]75\:\mathrm{seconds}[/tex]
Explanation:
The impulse-momentum theorem states that the impulse of an object is equal to the change in momentum of that object:
[tex]\Delta p=m\Delta v[/tex].
Impulse is also given by [tex]F\Delta t[/tex] where [tex]F[/tex] is the average net force and [tex]\Delta t[/tex] is change in time.
Therefore, we can set both equations equal to each other and solve:
[tex]\Delta p= F\Delta t[/tex].
Assuming that the airplane was initially at rest, its change in momentum is:
[tex]\Delta p =m\Delta v,\\\Delta p=30,000\cdot 50=1,500,000[/tex]
Impulse is represented using [tex]Ns[/tex]. Therefore, convert [tex]20\:\mathrm{kN}[/tex] to Newtons:
[tex]20\:\mathrm{kN}=20,000\:\mathrm{N}[/tex]
Thus:
[tex]1,500,000=20,000\cdot t,\\t=\frac{1,500,000}{20,000}=\fbox{$75\mathrm{s}$}[/tex].
Puck 1 is moving 10 m/s to the left and puck 2 is moving 8 m/s to the right. They have the same mass, m.
a. What is the total momentum of the system before the collision? (Answer in terms of the mass, m.) (0.5 points)
b. What is the total momentum of the system after the collision? (Answer in terms of the mass, m.) (0.5 points)
c. Write puck 1's velocity after the collision in component form. (1 point)
d. What is the y-component of puck 2's velocity after the collision? (1 point)
e. What is the x-component of puck 2's velocity after the collision? (1 point)
f. At what angle does puck 2 move after the collision? Determine the angle and draw it on the diagram. (1 point)
g. What is the magnitude of puck 2's velocity after the collision? (1 point)
Answer:
(a) the total momentum of the system before the collision = -2m kg.m/s.
(b) the total momentum of the system after the collision = -2m kg.m/s.
(c) puck 1's velocity after the collision in component form = (5.44 i, 2.54 j)
Explanation:
Given;
mass of Puck 1 , = m
mass of Puck 2, = m (since they have the same mass m)
initial velocity of Puck 1, u₁ = 10 m/s to the left
initial velocity of Puck 2, u₂ = 8 m/s to the right
Let the rightward direction be positive direction
Let the leftward direction be negative direction
(a) the total momentum of the system before the collision;
P₁ = (initial momentum of Pluck 1) + (initial momentum of Pluck 2)
P₁ = (-mu₁) + mu₂
P₁ = mu₂ - mu₁
P₁ = m(u₂ - u₁)
P₁ = m(8 - 10)
P₁ = -2m kg.m/s
(b) the total momentum of the system after the collision;
Based on the principle of conservation of linear momentum, the total momentum before collision is equal to the total momentum after collision.
Thus, the total momentum of the system after the collision is -2m kg.m/s.
(c) puck 1's velocity after the collision in component form
[tex]v = (v_x, v_y)\\\\v = (vcos \theta , vsin \theta)\\\\v = (6cos 25^0 , 6sin25^0)\\\\v = (5.44i, 2.54j)m/s[/tex]
Appliances connected so that they form a single pathway for
charges to flow are connected in a(n)
A. series circuit.
B. parallel circuit.
C. off circuit.
D. open circuit
Appliances connected so that they form a single pathway for charges to flow are connected in a(n)
Answer:A. Series circuit
#CARRYONLEARNING #STUDYWELLAppliances connected so that they create a single pathway for charges to flow are connected in a series circuit. Therefore, option (A) is correct.
What is the resistance of resistors connected in series?In a series combination of appliances, they are connected end-to-end. Consider two resistors, R₁ and R₂ which are connected in a series combination then their effective resistance can be given by:
Total Resistance of the series circuit, R = R₁ + R₂
In a series combination, the current flows through one appliance and then through another appliance. The same current flows through each appliance in one direction. The total voltage of the series circuit is equal to the sum of all the voltage drops across all appliances.
A potential difference of the series circuit, V = V₁ + V₂
Therefore, when appliances are connected in a series circuit they form a single pathway for charges to flow.
Learn more about resistors in series, here:
brainly.com/question/12400458
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The middle one please it’s due in 40 min
Answer:
3240000000 Joules
Explanation:
it serves as the fuctional unit of the nervous system
Answer:
i would say the neuron
explain how balanced and unbalanced forces effect an objects motion differently
Answer:
Balanced Forces will not change the object's motion.
Unbalanced Forces will change the object's motion.
Explanation:
The eagles suck, so do the giants and the jets and jaguars are irrelevant
anyone wanna argue
Naw ur pretty accurate, heck collage is the only football worth watching most the time. Hook'um horns!
When can a high speed velocity cause damage?'
Answer:
50 Mph.
Explanation:
According to the National Severe Storms Laboratory, winds can really begin to cause damage when they reach 50 mph. But here’s what happens before and after they reach that threshold, according to the Beaufort Wind Scale (showing estimated wind speeds): - at 19 to 24 mph, smaller trees begin to sway.
A ball falls from a tower
a) The two forces acting on the tennis ball are equal and opposite. What is the resultant force
?acting on the ball
Answer:
Zero
Explanation:
The resultant force acting on the ball would be zero.
Since only two forces were acting on the tennis ball and these forces negate and cancel each other in magnitude, the resultant effect on the tennis ball would be zero.
Assuming that one of the forces is 5N and acting from the positive side and the other force is also 5N but acting from the negative side.
Resultant = -5 + 5 = 0 N
A 50Kg girl jumps off a 5-meter-high diving board. What is her kinetic energy right before she
hits the water?
A. 0 J
B. 25 J
C. 1225 J
D. 2450 J
Answer:
D is the correct answer
Explanation:
Ek=m*g*h=50*9.8*5=2450
The kinetic energy right before she hits the water is 2450J. So, the correct option is D.
What is Kinetic energy?Kinetic energy is defined as the energy that is due to the motion of an object. If we want to accelerate an object, we must apply a force, by applying a force we need to do work. After the work is done, energy has been transferred to the object, and the object will continue to move with a new constant speed.
A 50Kg girl jumps off a 5-meter-high diving board.
We need to find the kinetic energy of the girl before she enters the water which means that the kinetic energy becomes equal to the potential energy such that,
P.E.=K.E. = mgh
where, m=mass of the object
g= acceleration due to gravity [tex](9.8m/s^2)[/tex]
h= height
So, K.E= 50* 9.8*5 = 2450 J
Thus, the kinetic energy right before she hits the water is 2450J. So, the correct option is D.
Learn more about Kinetic energy, here:
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A tennis ball is served horizontally from 2.4m above the ground at net is 12m away and point 0.9 high will be ball clear the net where will be ball land
Explanation:
Let us first calculate long does it take to go 12m at 30m/s( assumed speed)
12/30 = 0.4 seconds
horizontal distance the ball drop in that time
H= (0)(0.4)+1/2(-9.8)(0.4)2
H= -0.78m
negative sign shows that the height of the ball at the net from the top.
Height of the ball at the net and from the ground= H1-H=2.4-0.78=1.62m
As 1.62m>0.9m so the ball will clear the net.
H_1= V0y t’ + ½ g t’^2
-2.4= (0)t’ + ½ (-9.8) t’^2
t’= 0.69s
X’=V0x t’
X’=(30)(0.96)
X’= 20.7m
can someone please help me it’s 15 points of my major grade..
a.
b.
c.
e.
f.
g.
character limit thing
The phases of the moon are caused by which of the following
A. Earths rotation around its axis
B. Earths orbit around the sun
C. The moons orbit around the earth
D. Earths shadow falling on the moon
Answer: C: The moons orbit around the earth.
Explanation:
An object, 5 cm high, is placed on the principal axis of a diverging lens of focal length 20 cm. The object is 30 cm from the lens.
Use a scaled diagram to locate the image formed by the lens.
Answer:
The answer is 70 cm
Explanation:
If you add All the numbers together, you receive an 55 cm then you add 15 because the points on the diagram also count.
Help Please!
Think about how you can get the color white from using light versus how you can get the color white from using paint or dye. Now, think about how you can get the color black from using light versus from paint or dye. Using this, explain why we call coloring from light “additive” and coloring from paint or dyes “subtractive”.
Answer: Subtractive colors absorb OR subtract some lights causing it to reflect, and creating white.
Explanation:
Subtractive colors are created by completely or partially absorbing (or subtracting) some light wavelengths and reflecting others.
A jet aircraft is traveling at 262 m/s in horizontal flight. The engine takes in air at a rate of 85.9 kg/s and burns fuel at a rate of 3.92 kg/s. The exhaust gases are ejected at 921 m/s relative to the aircraft. Find the thrust of the jet engine. Answer in units of N Find the delivered power. Answer in units of W.
Answer:
[tex]F_T=60132.52N[/tex]
[tex]P=15814852.76W[/tex]
Explanation:
From the question we are told that
Velocity of aircraft [tex]V=263m/s[/tex]
Engine air intake rate [tex]\triangle M_a=85.9kg/s[/tex]
Fuel burn rate [tex]\triangle M_f =3.92kg/s[/tex]
Velocity of exhaust gas [tex]V_e =921m/s[/tex]
Generally the Mass change rate of Rocket is mathematically given by
[tex]\triangle M = \triangle M_a+\triangle M_f[/tex]
[tex]\triangle M= 85.9+3.92[/tex]
[tex]\triangle M=89.82kg/s[/tex]
Generally the Trust of the rocket is given mathematically by
[tex]F_T=(\triangle M *V_e)-(dM_a/dt)*(V)[/tex]
[tex]F_T=(89.82 *921)-(85.9)*(263)[/tex]
[tex]F_T=60132.52N[/tex]
Generally the Rocket's delivered power is mathematically given by
Delivered power P
[tex]P=V*F_T[/tex]
[tex]P=263*60132.52N[/tex]
[tex]P=15814852.76W.[/tex]
What type of electrical cord has a ground?
3 pronged cord
2 pronged cord
Explanation:
One prong is known as the hot wire, where the electricity comes in, while the second prong is the neutral wire and electricity leaves. Recall that a circuit must be made for electrons to flow. This means that electrons enters your house through the transmission wires and then the electrons leave along the same lines they entered (just along a different wire).
This set up describes a 2 pronged cord. Adding a third prong allows for a grounding to happen. In the event of an electrical surge, when too many electrons are flowing, disaster is likely to happen without some kind of safety features. The grounding prong allows electrons to seek the ground. You can think of it like a drain in a bathtub when too much water gets in the tub.
Answer:
3 pronged cord
Explanation:
ITS EASY TRUST ME!!!!
Answer:
it appears to be B. acceleration
How far will a car travel in 30 seconds at 12 m/s
Answer:
30*12=360m,it would travel 360 m.
A 4.00 kg block is pushed along the ceiling with a constant applied force of 85.0 N that acts at an angle of 55.0 degrees with the horizontal. The block accelerates to the right at 6.00 m/s2. Determine the coefficient of kinetic friction between block and ceiling.
Answer:
0.35
Explanation:
According to Newton's second law;
\sum Fx = ma
Fm - Ff =ma
Fm is the moving force = Wsin theta
Fm = 4(9.8)sin55
Fm = 32.1N
Ff is the frictional force = nmgcos theta
Ff = n(4)(9.8)cos55
Ff = 22.48n
Acceleration a = 6.0m/s²
Substitute the given values into the formula and get the coefficient of friction
32.11-23.48n = 4(6)
32.11-24= 23.48n
8.11 = 23.48
n = 8.11/23.48
n = 0.35
Hence the coefficient of friction is 0.35
Kinetic energy can be calculated using the formula KE = 1/2mv2. What is the kinetic energy of a bicycle that has a mass of 20 kg and is traveling at a velocity of 10 m/sec?
KE = 1000 J
General Formulas and Concepts:Math
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightPhysics
Energy
Kinetic Energy Formula: [tex]\displaystyle KE = \frac{1}{2}mv^2[/tex]
Energy is in Joulesm is mass (in kg)v is velocity (in m/s)Explanation:Step 1: Define
m = 20 kg
v = 10 m/s
Step 2: Find KE
Substitute [KE]: [tex]\displaystyle KE = \frac{1}{2}(20)(10)^2[/tex]Exponents: [tex]\displaystyle KE = \frac{1}{2}(20)(100)[/tex]Multiply: [tex]\displaystyle KE = (10)(100)[/tex]Multiply: [tex]\displaystyle KE = 1000[/tex]