Answer:
Gravitational energy and kinetic energy
The rock falls from the distance of 15 m before it hits the water. Calculate its kinetic energy just before hitting the water. Show your working
Answer:
[tex]k.e = \frac{1}{2} m {v}^{2} \\ {v}^{2} = {u}^{2} + 2gs \\ {v}^{2} = 0 + (2 \times 9.8 \times 15) \\ v = 17.1 \: m {s}^{ - 1} \\ k.e = \frac{1}{2} \times m \times {17.1}^{2} \\ = 147m \: joules \\ m \: is \: mass[/tex]
Kinetic energy of the rock just before hitting the water is 147m joules where m is the mass of the object.
What is Kinetic Energy?The kinetic energy of an object is defined as the energy it possesses due to its motion. It is the work required to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its acceleration, the body maintains the kinetic energy as long as its momentum does not change.
It is directly proportional to the mass of the object and the square of its velocity:[tex]K.E. = 1/2 mv^2[/tex].
Where, m= mass of the object
v= velocity
So if the units of mass are in kilograms and the units of velocity are meters per second, then kinetic energy has units of kilogram-meter squared per second squared.
For above given information,
[tex]K.E= 1/2 mv^2\\v^2= u^2 + 2gs\\ \\v^2= 0+ (2* 9.8*15)\\v^2= 294 m/s\\So, K.E. = 1/2 m* 294 m/s\\K.E.= 147m joules[/tex]
Thus, Kinetic energy of the rock just before hitting the water is 147m joules where m is the mass of the object.
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In an electrical circuit 200mC of charge flows through a 50kohm resistor in 90 seconds. What is the power
Answer: [tex]0.2464\ W[/tex]
Explanation:
Given
Charge [tex]Q=200\ mC[/tex]
Resistance [tex]R=50\ k\Omega[/tex]
Time [tex]t=90\ s[/tex]
Charge is the amount of current flown in a particular time
[tex]Q=It\\\Rightarrow 200\times 10^{-3}=I\times 90\\\\\Rightarrow I=\dfrac{200\times 10^{-3}}{90}\\\\\Rightarrow I=2.22\times 10^{-3}\ A[/tex]
Power is the given by [tex]P=I^2R[/tex]
Insert values
[tex]\Rightarrow P=\left(2.22\times 10^{-3}\right)^2\times 50\times 10^3\\\\\Rightarrow P=246.42\times 10^{-3}\ W\\\\\Rightarrow P=0.2464\ W[/tex]
The power is in the circuit is [tex]0.2464\ W[/tex].
The velocity of sound in a medium increases with increasing
a. distance
b. amplitude
c. temperature
d. time
c- temperature
The speed of sound increases with increasing temperature .
How can scientific phenomena be used in design?
A rope horizontally pulls a massive object lying on a surface with friction with a constant
velocity. What describes the force on the rope?
Answer:
Equal to the frictional force
Explanation:
Question; The options given with regards to a similar question posted online are;
A. Equal (equivalent) to the frictional force
B. Larger than the frictional force
C. Equal to the object's weight
D. More than the object's weight
Explanation
According to Newton's first law of motion, every object shall remain at rest or continue moving with uniform (constant speed) motion unless there is a net force acting on the object
Given that the velocity of the massive block, lying on the surface that has friction, being pulled by the rope = Constant
Therefore;
The net force acting on the moving block while being pulled by the rope = 0
From which we have;
The pulling force = The resistive force
Where;
The pulling force = The (pulling) force (applied) on the rope
The resistive force = The frictional force of the surface which tends to prevent the motion of the block
Therefore, given that the net force acting on the block = 0
The force on the rope = The frictional force (of the surface)
The correct option is option A. Equal to the frictional force.
Trafegando por uma avenida com velocidade constante de 54km/h, num dado instante, o motorista percebe o sinal vermelho à sua frente e pisa no freio até que, depois de 5 s, o automóvel para. Determine a aceleração escalar média do carro nesse intervalo de tempo em Km/h dividido por s e em m/s²
Answer:
The acceleration is - 3 m/s2.
Explanation:
initial speed, u = 54 km/h = 15 m/s
final speed, v = 0
time, t = 5 s
Let the acceleration is a.
use first equation of motion
v = u + at
0 = 15 + a x 5
a = - 3 m/s2
Which force determines if an object is going to move or stay at rest?
a. Friction Force
b. Normal Force
c. Applied Force
d. Net Force
Answer:
a
Explanation:
because it's need someone moving it so it can move somewhere else
the volume of vessel is 6 litres. convert it into ml
An object is fired from the ground at 100. m/s at an angle of 30° with the horizontal.
a) Calculate the horizontal and vertical components of the initial velocity
b) After 2.0 seconds, how far has the object traveled in the horizontal direction?
c) How high is the object at this point
Answer:
a. V_y = 50m/s and V_x = 86.6m/s
b. d_x = 173.2m
c. d_y = 80.38m
Explanation:
V_x = 100m/s*cos(30°)
V_x = 86.6m/s
V_y = 100m/s*sin(30°)
V_y = 50m/s
D_x = v_x*t
d_x = 86.6m/s*2s
d_x = 173.2m
v_f = 50m/s+(-9.81m/s²)*2s
v_f = 30.38m/s
d_y = .5*(30.38m/s+50m/s)*2s
d_y = 80.38m
I pull a wagon with a 30 kg child in it with a FORCE of 2000 N. The handle makes a 60 degree angle with the horizon. If I pull the child for a distance of 0.75 miles (1 mile = 1600 m), how much work did I do?
Answer:
1200000 J
Explanation:
Applying,
W = Fdcos∅....................... Equation 1
Where W = Workdone, F = Force applied to pull the wagon, d = distance, ∅ = angle with the horizontal.
From the question,
Given: F = 2000 N, d = 0.75 miles = (0.75×1600) = 1200 m, ∅ = 60°
Substitute these values into equation 1
W = 2000×1200×cos60°
W = 2000×1200×0.5
W = 1200000 J
Hence the work done in pulling the wagon is 1200000 J
if a wire with current 5.0a has 12 coulombs of charge pass through it how much time has passed
Answer:
2.4 secs.
Explanation:
Current (A) = Charge (coulomb)/Time(sec)
We are looking for time. So:
Time (sec) = Charge (coulomb)/Current (A)
↓
12coulombs/5.0A = 2.4 secs
Which statement describes the possible interaction(s) between two objects
caused by the electric, magnetic, or gravitational force between them?
O A. Electric and gravitational forces only cause objects to repel each
other, and magnetic forces only cause objects to be attracted to
each other.
O B. All three types of forces only cause the objects to repel each other.
O C. Gravitational forces only cause objects to be attracted to each
other, and magnetic and electric forces can cause objects to
attract or repel each other.
O D. All three types of forces only cause the objects to be attrachyd to
each other.
The statement which describes the possible interaction(s) between two objects caused by the electric, magnetic, or gravitational force between them is:
Gravitational forces only cause objects to be attracted to each other, and magnetic and electric forces can cause objects to
What is force?Force can be defined as the push or pull on an object with mass that causes it to change its velocity
So therefore, the statement which describes the possible interaction(s) between two objects caused by the electric, magnetic, or gravitational force between them is:
Gravitational forces only cause objects to be attracted to each
other, and magnetic and electric forces can cause objects to
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A motor has an internal resistance of 12.1 Ω. The motor is in a circuit with a current of
4.0 Amps
What is the voltage?
Answer:
Explanation:
V = I * R
V = 4 * 12.1 = 48.4 v
Which refers to the ratio of output force to input force of a machine?
mechanical advantage
average strength
total power
energy requirement
Answer:
mechanical advantage
Explanation:
i got it right on edge :)
If the light ray hits the first mirror and continues to bounce off the other mirrors inside the box, determine where the light ray will eventually hit on the border
Answer: Light ray X will eventually hit the borader
Explanation:
For the normal force in the drawing to have the same magnitude at all points on the vertical track, the stunt driver must adjust the speed to be different at different points. Suppose, for example, that the track has a radius of 3.25 m and that the driver goes past point 1 at the bottom with a speed of 20.2 m/s. What speed must she have at point 3, so that the normal force at the top has the same magnitude as it did at the bottom
Answer:
The speed she must have at point 3 is approximately 21.72 m/s
Explanation:
The given parameters are;
The radius of the track, r = 3.25 m
The speed with which the driver goes past point 1, v₁ = 20.2 m/s
Let, 'm', represent the mass of the driver and the car, and let v₃ represent the velocity at point 3, based on the diagram and solution method from a similar question online, we have;
At point 1, The net force, [tex]F_{NET} = F_N - F_g[/tex]
The net force, [tex]F_{NET}[/tex], is the centrifugal force, therefore;
[tex]F_{NET} = \dfrac{m \cdot v_1^2}{r}[/tex]
[tex]F_g[/tex] = The force of gravity on the car (the weight of the car) = m·g
[tex]F_N_1[/tex] = The normal reaction at point 1
Therefore, we have;
[tex]F_{NET} = \dfrac{m \cdot v_1^2}{r} = F_N_1 - F_g = F_N_1 - m \cdot g[/tex]
[tex]F_N_1= \dfrac{m \cdot v_1^2}{r} + m \cdot g = m\cdot \left(\dfrac{ v_1^2}{r} + g \right)[/tex]
[tex]F_N_1 = m\cdot \left(\dfrac{ v_1^2}{r} + g \right)[/tex]
At point 3, The net force, [tex]F_{NET} = F_N_3 + F_g[/tex]
Where;
[tex]F_{N3}[/tex] = The normal reaction at point 3
Therefore;
[tex]F_N_3= F_{NET} - F_g = \dfrac{m \cdot v_3^2}{r} - m \cdot g = m\cdot \left(\dfrac{ v_3^2}{r} - g \right)[/tex]
For the normal force to be the same, we get;
[tex]F_{N1} = F_{N3}[/tex]
Therefore;
[tex]m\cdot \left(\dfrac{ v_1^2}{r} + g \right) = m\cdot \left(\dfrac{ v_3^2}{r} - g \right)[/tex]
[tex]\left(\dfrac{ v_1^2}{r} + g \right) = \left(\dfrac{ v_3^2}{r} - g \right)[/tex]
[tex]v_3^2 = r \times \left(\dfrac{ v_1^2}{r} + g + g \right) = v_1^2 + 2\cdot g \cdot r[/tex]
[tex]v_3 = \sqrt{v_1^2 + 2\cdot g \cdot r}[/tex]
Where;
g = The acceleration due to gravity ≈ 9.81 m/s²
Therefore;
v₃ = √(20.2² + 2 × 9.81 × 3.25) ≈ 21.72 m/s
The speed she must have at point 3, so that the normal force at the top has the same magnitude as it did at the bottom, v₃ ≈ 21.72 m/s
what current flows between a voltage of 120v across a resistance of 30Ω?
Answer:
4 amp
Explanation:
From ohm's law,
V=IR
so,
I=V/R
I=120/30
I=4amp ans..
Dierks is a scientist who is currently focusing on developing a ceramic that holds heat well. He is trying to develop the ceramic to make a higher-temperature curling iron. The application of solid-state physics Dierks is most likely involved in is (BLANK).
Answer:
i need this 2
Explanation:
Answer:
Materials Science
Explanation:
Materials Science: "The study of the characteristics of materials such as glass, plastics, and metals."
Ceramics is a glass so they are studying materials science.
Hope this helped ! :)
What is work and give an example? (science newton's law)
Answer:
Work is ability if application of energy.
Such as pushing a wheel barrow through a distance ( Newton's third law )
Work is the ability to do something.
a drop of oil of volume 10^-10 cubic metre spreads out on water to make a circular film of radius 10^-1 metre. what is the thickness of the film?
Answer:
[tex]h=3.18\times 10^{-9}\ m[/tex]
Explanation:
Given that,
The volume of a drop, [tex]V=10^{-10}\ m^3[/tex]
The radius of the circular film, [tex]r=10^{-1}\ m[/tex]
We need to find the thickness of the film.
We know that,
Volume, [tex]V=\pi r^2 h[/tex]
So,
[tex]h=\dfrac{V}{\pi r^2}\\\\h=\dfrac{10^{-10}}{\pi \times (10^{-1})^2}\\\\h=3.18\times 10^{-9}\ m[/tex]
So, the thickness of the file is equal to[tex]3.18\times 10^{-9}\ m[/tex].
define pressure snd state its SI units to
Pressure is defined as the perpendicular force acting per unit area.
Its SI unit is pascal.
Explanation:
Formula to calculate pressure is,
P=F/A
Where as,
P = Pressure
F = Force
A = Area
Its SI unit is pascal(pa).
a magnetic field will move-
a) magnets and moving charged particles.
b) only other magnets.
c) only uncharged particles.
d) only moving charged particles.
Every day, every hour, every second one of the most important events in life is going on in your body—cells are dividing. When cells divide, they make new cells. A single cell divides to make two cells and these two cells then divide to make four cells, and so on. We call this process "cell division" and "cell reproduction," because new cells are formed when old cells divide. The ability of cells to divide is unique for living organisms. 3.A) _________ is a type of cell division which results in the formation of gametes. *
Answer:
the answer to the question is mitosis
a man runs 1200m on a straight line in 4 min . find his velocity.
Answer:
5m/sec^2
Explanation:
Distance=1200m
Time=4 min
1=60sec
4=4 x 60
=240sec
Velocity=Distance/Time
Velocity=1200/240
Velocity=5m/sec^2
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Which state has the most fixed shape?
O A. Gas
O B. Solid
O C. Liquid
O D. Plasma
Answer: Liquid
“A substance will take on the shape of an open container if it is a Liquid. Explanation: The major state of matter are solid, liquid and gas. Liquid usually have a definite volume.”
Answer:
solid
Explanation:
Solids are fixed and solid.
give an example of a body with uniform acceleration
Answer:
A ball rolling down the slope.
A bicycle rider is riding the bicycle on tthe slope where both pedals are engaged.
A piece of glass has mass of 1 kg and a density of 800 kgm-³ negative cubed calculate its volume
Explanation:
we know that
v = m/d
or; v=1kg/800kgm^3
or; v=0. 00125m
anyone know how to do this?
The voltage from one side of the battery all the way around to the other side of the battery is 12v .
If 4 of those volts show up across the circle-thing, then the rest of the 12v ... 8v ... Must show up across the set of parallel rectangles.
To get that answer, I subtracted the 4 from the 12.
Just like it says in choice-C.
what is accerlation due to gravity??
Answer:
When an object falls, gravity pulls the object towards the ground and causes the object to accelerate by 9.8m/s each second. Regardless of mass, every object accelerates at the same rate (9.8m/s) when dropped unless there´s air resistance.
Find the resultant of these two forces : 2.00 x 10^2 N due east and 4.00 x 10^2 N 30.0 degree north of west
If two vectors are represented both in magnitude and direction by the two adjacent sides of a triangle taken in an order, then their resultant is given by the third side taken in the reverse order.
Resultant vector :
R = sqrt of A^2 + B^2 + 2ABcosθ
given :
A = 200 units
B = 300 units
θ = 30 degrees
∴ R = sqrt of 200^2 + 300^2 + 2(200)(300)cos35
the answer is 477.805656