Answer:
Force = 35 N
Explanation:
From Newton's third law of motion, the boy must apply a force greater than the weight of the sled to lift it.
weight of sled = mg
where m is its mass and g the force of gravity on it.
weight of sled = 50 N
Force applied by the boy on the sled = 15 N
Since the force applied on the sled by the boy is lesser than the weight of the sled, then;
Force that the sled exerts on the student = 50 - 15
= 35 N
The force exerted by the sled on the student is 35 N.
A density of solid 13g/cm³ at a temperature of 25°c was now heated to a temperature of 150°c find the new density of the solid ? Given linear expansivity to be 2 × 10⁻⁵ ?
Answer:
13.4225 g/cm³
Explanation:
Given that:
Linear expansivity α = 2 * 10^-5
Change in temperature dt = t2 - t1 = (150 - 25)°c = 125°c
Initial density (d1) = 13
New density d2 =?
Using the relation :
α = (d2 - d1) / d1 * dt
d2 - d1 = d1 * dt * α
d2 = d1 + d1*dt*α
d2 = d1(1 + d1*dt*α)
d2 = 13( 1 + (13*125*2*10^-5))
d2 = 13(1 + 0.0325)
d2 = 13(1.0325)
d2 = 13.4225
d2 = 13.4225 g/cm³
What is the distance between a 2000 kg truck and a 3000 kg truck if the gravitational force between them is 0.00006 N?
A 258
B. 567 m
C 981
D. 15
Answer:
A. 2.58m
Explanation:
Using the formula;
F = GMm/r²
M and m are the masses
G is the gravitational constant
r is the distance between the masses
Substitute
0.00006 = 6.67*10^-11(2000)(3000)/r²
0.00006r² = 6.67*10^-11*6000000
0.00006r² = 40.02*10^-5
0.00006r² = 0.0004
r² = 0.0004/0.00006
r² = 6.66
r = 2.58m
Hence the distance between them is 2.58m
When a hammer strikes a nail, the nail..
exerts balanced forces that helps it from moving.
exerts a force equal to the weight of the hammer..
exerts an unbalanced force that changes its velocity.
exerts an equal and opposite force back on the hammer.
Answer:
Could you possible elaborate on the question more?
Answer:
eH?
Explanation:
work done by a gravitational force by lowering the bucket into the well is
Answer:
when we lower a bucket into a well to fetch water, the work done by gravity is positive since force and displacement are in the same direction.
Explanation:
question is attached!
Answer:
For Bill to dump the water on Tim, Tim should be 7.232 meters from the tree when Bill dumps the water
Explanation:
The given height above the ground at which Bill sits on the tree branch with a bucket of water, h = 4.0 meters
The speed with which Tim is approaching the tree = 8.0 meters per second
The time , t, it will take for the bucket of water to reach the ground is given by the equation of free fall as follows;
h = 1/2·g·t²
Where;
h = Height = 4.0 m
g = The acceleration due to gravity ≈ 9.8 m/s²
t = The time
Making t the subject of the above equation gives;
t = √(h/(1/2·g))
Substituting the known values gives;
t = √(4.0 m/(1/2 × 9.8 m/s²)) ≈ 0.904 s
t ≈ 0.904 seconds
Therefore, for Bill to dump the water on Tim, it should take Tim approximately 0.904 seconds to get to the tree
The distance, d, Tim will be when it will take him 0.904 seconds to get to the tree is given from the kinematic equation of speed, s, as follows;
Distance, d = Time, t × Speed, s
Where;
d = The distance
t = The time = 0.904 s
s = The speed with which Tim is approaching the tree = 8.0 m/s
Substituting the values gives;
d = 0.904 s × 8.0 m/s = 7.232 m
Therefore, the distance Tim should be when Bill throws the water = 7.232 meters
A constant horizontal F force began to act on the initially immovable body placed on a horizontal surface. After t time the force ceased to act, and after time 3t from the start of the movement the body stopped. Find the coefficient of friction between the body and the surface if the body mass is m.
Answer:
The coefficient of friction is (F/(19.6·m)
Explanation:
The given parameters are;
The force applied to the immovable body = F
The time duration the force acts = t
The time the body spends in motion = 3·t
The acceleration due to gravity, g = 9.8 m/s²
From Newton's second law of motion, we have;
The impulse of the force = F × t = m × Δv₁
Where;
Δv₁ = v₁ - 0 = v₁
The impulse applied by the force of friction, [tex]F_f[/tex] is [tex]F_f[/tex] × (3·t - t) = [tex]F_f[/tex] × (2·t)
Given that the motion of the object is stopped by the frictional force, we have;
The impulse due to the frictional force = Momentum change = m × Δv₂ = [tex]F_f[/tex] × (2·t)
Where;
Δv₂ = v₂ - 0 = v₂
Given that the velocity, v₂, at the start of the deceleration = The velocity at the point the force ceased to act, v₁, we have;
m × Δv₂ = [tex]F_f[/tex] × (2·t) = m × Δv₁ = F × t
∴ [tex]F_f[/tex] × (2·t) = F × t
[tex]F_f[/tex] = F × t/(2·t) = F/2
The coefficient of dynamic friction, [tex]\mu _k[/tex] = Frictional force/(The weight of the body) = (F/2)/(9.8 × m)
[tex]\mu _k[/tex] = (F/(19.6·m)
The coefficient of friction, [tex]\mu _k[/tex] = (F/(19.6·m)
Will mark the brainliest
When a car of mass 1000kg is travelling along a level road at a steady speed of 20ms −1
its engine is working at 18kW.
Resultant force = 900N Braking Force = 3100N Gravity = 9.81
By how much does this change if the car is travelling down the same hill at 20ms −1 ?
Answer:
OK draw a diagram - you have the force from (b) acting sown the slope and a component of the weight. Use F=ma to get the deceleration and then use SUVAT. Post your working if this doesn't work.
friction = 900N
braking = 3100N
total = 4000N
w= mxg = 1000*9.81= 9810N
total = 9810 + 4000 = 13810N
force/mass = 13810/1000 = 13.81ms^-2
then using v^2 = u^2 + 2as, i get s as 14 but it is incorrect
Explanation:
where would you expect light waves to move faster?
a - in space
b- through an iceberg
c- under the sea
d- on a mountain top
Answer:
a
Explanation:
In pulling two identical carry-on bags through the airport, Mr. Myers and his 13 year old grandson, Vincent, do the same amount of work. Who has to use a greater force between gates?
Answer:
Mr Myers and his son use the same force to pull the bags between the gates
Explanation:
The work done by Mr. Myers in pulling the carryon bags = The work done by his 13 year old grandson in pulling the identical bag
Let F₁ represent the force used by Mr Myers, and let F₂ represent the force F₂ used by his grandson
Let d represent the distance through the gate
Therefore, given that Work done, W = Force, F × Distance, we have;
The work done by Mr Myers between the gates, W₁ = F₁ × d
The work done by his grandson between the gates, W₂ = F₂ × d
Where, the work done by both Mr Myers and his grandson are equal, we have;
W₁ = W₂ and therefore, F₁ × d = F₂ × d, which gives;
F₁ = F₂, the force used by both Mr Myers and his son between the gates are equal.
Efficiency is a measure of how much of the work put into a machine is converted into useful output work. Why can efficiency never reach 100%?
A) Acceleration
B) Elasticity
C) Friction
D) Gravity
Answer:
C , Friction
Explanation:
HELP ASAP!!!!!!! PLEASE WILL GIVE BRAINLIEST
Name the three major parts of a cell and their functions
Answer:
Cell Membrane (Plasma Membrane)
Cytoplasm.
Nucleus.
Explanation:
The cytoplasm is home to many activities of the cell as it contains molecules, enzymes that are crucial in the break down of the waste. The cytoplasm also assists in metabolic activities. Cytoplasm provides shape to the cell. It fills up the cells thus enabling the organelles to remain in their position.
The plasma membrane, or the cell membrane, provides protection for a cell. It also provides a fixed environment inside the cell. And that membrane has several different functions. One is to transport nutrients into the cell and also to transport toxic substances out of the cell.
The nucleus controls and regulates the activities of the cell (e.g., growth and metabolism) and carries the genes, structures that contain the hereditary information. Nucleoli are small bodies often seen within the nucleus.
Fig. 2.1 shows the extension-load graph for a spring.
extension
06
load
Fig. 2.1
Dint P is the limit of proportionality.
:) (0) Name the law obeyed by the spring from the origin to P.
[1]
(ii) Describe two features of the graph which show that the law is obeyed.
2.
[2]
-) On Fig. 2.1, sketch a possible continuation of the graph when the spring is loaded
beyond the limit of proportionality.
Answer:
(1) Hooke's law
(2) a) Extension is directly proportional to the applied load
b) The starting point of the graph is the origin (0, 0) or absence of load, no extension
Explanation:
(1) The law obeyed by the spring is known as Hooke's law which states that the extension or compression, x, of a spring proportional to the applied force, F
F = -k × x
Where;
k = The spring constant
(2) Given that the law mathematically is F = -k × x
The two features of the graph that show that the law is obeyed are;
a) The extension increases as the load is increased
b) The extension is zero when the there is no applied load.
11. A ball is thrown up and attains maximum height of 20 m. Calculate its initial speed. (g = 10 ms')
a) 19.7 m/s
b) 20 m/s
c) 25 m/s
d) 35m/s
final velocity = 0
acceleration = - 10 m/ s 2
distance. = 20 m
u = ?
v^2 - u ^2 = 2 a s
0^2 - u^ 2 = 2 * -10 * 20
-u^2 = -400
u = √ 400
u = 20m / s
Write the newtons formula for the velocity of sound in air .how did Laplace correct this formula ?
Answer:
1: v = √E/ρ where E is the elasticity and ρ is the density. Newton's assumed that sound wave travel in air under isothermal condition
2: He corrected Newton's formula by assuming that, there is no heat exchange takes place as the compression and rarefaction takes place very fast. Thus, the temperature does not remain constant and the propagation of the sound wave in air is an adiabatic process.
How do minerals crystallize or form in veins ?
Answer:
For example, when magma heats water deep underground, elements and compounds in the surrounding rock will dissolve in the water, forming a solution. ... The cooling process causes them to crystalize and form minerals inside the rock. These are called veins
A pendulum on earth oscillates with a period of 3.45 seconds. What is the length of the pendulum?
Answer:
The length of the pendulum is 2.954 m.
Explanation:
Given;
period of the pendulum, T = 3.45 s
The period of the pendulum oscillation is given as;
[tex]T = 2\pi \sqrt{\frac{l}{g} } \\\\\frac{T}{2\pi} = \sqrt{\frac{l}{g} }\\\\\frac{T^2}{4\pi ^2} = \frac{l}{g} \\\\l = \frac{gT^2}{4\pi ^2} \\\\[/tex]
where;
L is length of the pendulum
g is acceleration due to gravity on Earth = 9.8 m/s²
[tex]l = \frac{gT^2}{4\pi ^2}\\\\l = \frac{(9.8)(3.45)^2}{4\pi ^2}\\\\l = 2.954 \ m[/tex]
Therefore, the length of the pendulum is 2.954 m.
How high must you lift a 25 Newton book for it to have the same increase in potential energy as a 20 Newton book that was lifted to 0.5 meters?
Given :
An object with weight 20 N was lifted to 0.5 meters.
To Find :
How high must you lift a 25 Newton book for it to have the same increase in potential energy as the given book.
Solution :
Since both have same potential energy :
[tex]P.E_2 = P.E_1\\\\W_2h_2 = W_1h_1[/tex]
Putting all given values in above equation :
[tex]25h_2 = 20\times 0.5\\\\h_2 = \dfrac{20\times 0.5}{25}\\\\h_2 = 0.4\ m[/tex]
Therefore, book with same potential energy is at a height of 0.4 m.
23. If a jogger runs 100 meters west and then turns around and runs 30 meters east. What
was the jogger's displacement?
a. 70 meters.
b. 130 meters.
C. 30 meters.
d. 100 meters.
Answer:
A
Explanation:
if he goes to the west, the east is opposite so 100-30
The jogger's displacement was 70 meters. Hence, option (a) is correct answer.
What is displacement?The term "displacement" refers to a shift in an object's position. The symbol for it is an arrow pointing from the initial location to the ending place.
Displacement is a vector quantity as both magnitude and direction are required for defining displacement. SI unit of Displacement is meter.
Given parameter:
The first displacement of the jogger is = 100 meters along west direction.
The second displacement of the jogger is = 30 meters along east direction.
Hence, resultant displacement of the jogger along west direction = 100 meters - 30 meters
= 70 meters.
Hence, the magnitude of jogger's displacement was 70 meters. Hence, option (a) is correct answer.
Learn more about displacement here:
https://brainly.com/question/11934397
#SPJ2
what is the relation between distance and speed
by the formula
s=d/t
speed=distance/time
the bigger the distance that has been traveled over a period of time the bigger the speed
Speed = Distance / Time
If time is held constant, then speed is directly proportional to distance. If distance is held constant and time varies, then the speed is inversely proportional to the time taken.
When the notebook is sitting on the table, what force prevents it from falling into the space below the table? If you don’t know the name of this force, just describe it. What force keeps the notebook from floating in the air?
Answer:
reaction force/normal force (its when the tables kinda pushing from under so it doesnt fall)
and the notebook wont float bc of gravity
Explanation:
theres a quizlet on this if you wanna check it out lol
Answer:
The table surface pushes the notebook from below and prevents it from falling. (This force is called the normal force.) Gravity, or a pull from Earth, keeps the notebook from floating in the air.
Explanation:
who is the best soccer player?
A bucket filled with water has a mass of 70kg and is hanging from a rope that is wound around a 0.054 m radius stationary cylinder. If the cylinder does not rotate and the bucket hangs straight down, what is the magnitude of the torque the bucket produces around the center of the cylinder?
Answer:
T = 37.08 [N*m]
Explanation:
We must remember that torque is defined as the product of a force by a distance. This distance is measured from the point of application of force to the center of rotation of the rotating body.
The force is equal to the product of mass by gravitational acceleration.
[tex]F=m*g\\F=70*9.81\\F=686.7[N][/tex]
Now the torque can be calculated:
[tex]T=F*r\\T=686.7*0.054\\T=37.08[N*m][/tex]
A balloon tied up with a wooden piece is moving upward with velocity of 15m/s. At a height of 300m above the ground, the wooden block detached from the balloon. How much time will it take to reach the ground?
What can the vacuole hold? (check all that apply)
A) water
B) waste
C) nutrients (food)
Answer:
C & A 100000%
Explanation:
i took this test before and i just made sure on safari . Its food (nutrients) and water
A rope hangs between two cliffs, edge A and edge B. There is a 250 kg hiker sliding across and is closer to
edge A than edge B. The angles that the ropes make below the horizontal are 35° below edge A and 65° below
edge B. What is the Tension in both ropes?
Answer:
1655.5 N
Explanation:
We resolve the forces on the rope into horizontal and vertical components. Since the only vertical force exerted on the rope is the weight of the man, this weight equals the vertical components of the tensions on both sides of the rope .
The only horizontal forces acting on the rope are horizontal components of both tensions on both sides. Since the hiker doesn't move sideways, they cancel out and he is balanced. So, the net horizontal force is zero.
Let T be the tension in the rope. So, each vertical component on side A is Tsin35° and that on side B is Tsin65°. Let the weight of the man be W = mg where m = mass of hiker = 250 kg and g = acceleration due to gravity = 9.8 m/s².
So, since the hiker balances, Tsin35° + Tsin65° = mg
0.5736T + 0.9063T = 250 kg × 9.8 m/s²
1.4799T = 2450 N
dividing both sides by 1.4799, we have
T = 2450 N/1.4799
T = 1655.52 N
T ≅ 1655.5 N
So, the tension in the rope equals T = 1655.5 N
A solar-powered car has a kinetic energy of 110250 J. Its mass is 180 kg. Work out how fast the car is travelling.
Answer:
35 m/s
hope this helpedd
Explanation:
Kinetic Energy 1 upon 2 into mass into velocity square
1 upon 2 into 180 into velocity square=110250
v^2=110250 multiple by 2 and divided by 180
And take square root
A student decides to make some extra money during a snow day. As the neighborhood kids are outside sledding, the student offers to pull the students to the top of the hill for one dollar per ride. The sled-puller noticed that it was taking more time to pull older children to the top than with the younger children even though they were pulling with the same force.
Explain why some kids took longer to pull to the top of the hill then other kids despite pulling with the same force. Be sure to address the following for 2 points each:
Identify the formula used to calculate the force of each pull up the hill.
Identify what was different about the older children compared to the younger children that affected the trips up the hill
Explain how this demonstrates Newton's Second Law of Motion
Answer: 5.5 mass
Explanation: The force of gravity pulling the car up the hill = 5.5
Which characteristic of a sound is affected by the amount of energy used to create that sound? In what direction the sound will travel how fast or slow the sound travels in a particular medium how high or low the sound's pitch is how loud or soft the sound is
Answer:
The correct option is;
How loud or soft the sound is
Explanation:
The loudness of a sound wave is given by the amount of energy that the pressure wave carries and it is measured in decibels (dB) which is the relative intensity of the pressure wave of a sound to the standard pressure
A loud sound has a high amplitude and a soft sound has a low amplitude, such that as the amplitude of the sound is increased, due to increased energy input, the sound becomes louder, and as the amplitude of the sound is decreased due to reduced energy input, the sound becomes softer.
Which type of fault is shown by the illustration below where the hanging wall moves down relative to the foot wall?
A. normal fault
B. reverse fault
C. strike slip fault
D. thrust fault
Answer:
A. normal fault NOT
B. reverse fault YES IT IS
Explanation:
I hope this helps
Have a Blessed Day
2. Explain how the number of batteries and the number of coils of wire affect the strength of an electromagnet.
Answer:
The more the number of batteries and coils, the more the electromagnetism.
Explanation:
An electromagnet is a structure formed by passing electricity through a good conductor. Due to the 'Magnetic Effect Of Electric Current', the object functions as an electromagnet, that is, by attracting magnetic objects to it.
This intensity of electromagnetism is greatly dependent on the Electric flow or Current as well as the Number of coils on the electromagnet.
By increasing the number of coils in the electromagnet, you actually increase the electric flow per area or the Magnetic Induction, helping to broaden its magnetic field.
The more batteries you connect to a circuit, the more will be its voltage. Similarly, the more batteries you connect to an electromagnet, the greater will be its strength, due an increased flow of electrons.