Answer:
Parallel
Explanation:
The work done is defined as the force applied on an object and the displacement in the position of the object in the direction of force.
W = F s cos A
where, F is the force, s is the displacement and A is the angle between force and displacement.
When the angle between the force and the displacement is 90 degree, the work done is zero.
To get the maximum work the angle between the force and the displacement is 0 degree.
So, to get the work done by the force the angle between the force and displacement is 0 degree that means the force and displacement is parallel to each other.
A motorcycle moving with velocity and 30m/s accelerate with 4m/s2 to gain velocity of 6mls. calculate its time to gain that velocity
Using first equation of kinematics
[tex]\boxed{\sf v=u+at}[/tex]
[tex]\\ \sf\longmapsto t=\dfrac{v-u}{a}[/tex]
[tex]\\ \sf\longmapsto t=\dfrac{30-6}{4}[/tex]
[tex]\\ \sf\longmapsto t=\dfrac{24}{4}[/tex]
[tex]\\ \sf\longmapsto t=6s[/tex]
Is velocity ratio of a machine affected by applying oil on it?Explain with reason.
Answer:
It depends upon SAE No. of oil. (SAE means Society of Automotive Engineers). However, it usually does protect against friction.
Explanation:
If we use very viscous oil, it does not reach all the parts. Very thin oil will flows away easily and gets wasted. Grease is used in such cases. It is generally used around ball-bearing. Normal grease or oil is never used where there is high pressure, high temperature and high speed. Special lubricants are used in such cases. In cold season the oil becomes thick and in hot season it becomes thin. Therefore selection of lubrication also depends on the season. It is always advisable to refer operating manual of the equipment before selecting the lubricant.
The intensity of friction depends on following factors:
i) The area involved in friction.
ii) The pressure applied on the surfaces.
Force = Pressure ´ Area Frictional force will increase, if the area of contact will increase or if pressure applied on the surface increased.
A red car has a head-on collision with an approaching blue car with the same magnitude of momentum. A green car driving with the same momentum as the other cars collides with an enormously massive wall. Which of the three cars will experience the greatest impulse
All three cars experience the same impulse.
Impulse is equal to change in momentum.
Each car starts with the same amount of momentum and ends up with zero, so the magnitudes of all three changes are equal.
A cricket ball of mass 800g has momentum of 20 kg m/sec . Calculate velocity of ball
Answer: 25 m/s
Explanation:
1. rearrange equation p = mv to find v
2. v = p/m - then convert 800 g into kg (= 0.8 kg)
3. plug in p and m - v = 20 / 0.8 = 25 m/s
Answer:
V= 25m/s
Explanation:
Mass=800g
Momentum=20kgm/s
V= ?
Convert 800g to kg
800/1000 = 0.8kg
Momentum=mass× Velocity
Momentum/Mass = Velocity
20/0.8 =25m/s
You are pushing a cart at the grocery store. The cart is speeding up. a) When your friend drops a 50 pound bag of dog food into the cart you are pushing, what would happen to the acceleration of the cart? Explain your answer using Newton's Second Law.
Answer:
The acceleration will decrease/reduce
Explanation:
Newton in his second law of motion states that the acceleration of an object is dependent on the force and mass applied on the object. Using the equation as follows:
F = m × a
Where;
F = force (N)
m = mass (kg)
a = acceleration (m/s²)
Acceleration (a) is directly proportional to the force (F) applied but inversely proportional to the mass (m).
According to this question, a friend drops 50 pounds of dog food into a cart being pushed with speed. This means that the mass/weight of the cart was increased. Since the acceleration is inversely proportional to the mass of an object, this means that the acceleration of the cart will DECREASE/REDUCE as the mass increases.
Which of the following changes would not lead to changes in the efficiency of
a heat engine?
A. Doubling the work done while keeping the heat flow into the
engine the same
B. Doubling the heat flow into the engine while halving the work done
C. Doubling both the work done and the heat flow into the engine
D. Doubling the heat flow into the engine while keeping the work
done the same
Explanation:
B. Doubling the heat flow into the engine while halving the work done
hope this helps you
have a nice day
pls someone help me pls…. and pls explain to me how
Answer:
1.12 × 10⁴ m/s
Explanation:
The escape velocity of the object v = √(2GM/R) where G = gravitational constant = 6.67 × 10⁻¹¹ Nm²/kg², M = mass of the Earth = 6 × 10²⁴ kg and R = radius of the Earth = 6.4 × 10⁶ m
Since v = √(2GM/R)
Substituting the values of the variables into the equation, we have
v = √(2GM/R)
v = √(2 × 6.67 × 10⁻¹¹ Nm²/kg² × 6 × 10²⁴ kg/6.4 × 10⁶ m)
v = √(13.34 × 10⁻¹¹ Nm²/kg² × 6 × 10²⁴ kg/6.4 × 10⁶ m)
v = √(80.04 × 10⁻¹¹ × 10²⁴Nm²/kg/6.4 × 10⁶ m)
v = √(80.04 × 10¹³Nm²/kg ÷ 6.4 × 10⁶ m)
v = √(80.04 ÷ 6.4 × 10¹³ ÷ 10⁶Nm/kg)
v = √(12.50625 × 10⁷ Nm/kg)
v = √(125.0625 × 10⁶ Nm/kg)
v = 11.18 × 10³ m/s
v = 1.118 × 10 × 10³ m/s
v = 1.118 × 10⁴ m/s
v ≅ 1.12 × 10⁴ m/s
Provide two positives and two negatives the Sarah‘s family would face if they switched to organic farming
Answer:
Organic farming would have higher costs, and would be more complex than conventional farming. However, the Suarez family could charge a higher price for organic produce. This type of farming also would be better for the land.
Explanation:
Answer expert verified for the same question. (question/4178423)
We use __force to do different force. 1) pulling 2)pushing 3)gravity 4)muscular
Answer:
gravity
Explanation:
We use gravity to do different force.
There are four charges, each with a magnitude of 4.25 C. Two are positive and two are negative. The charges are fixed to the corners of a 0.440-m square, one to a corner, in such a way that the net force on any charge is directed toward the center of the square. Find the magnitude of the net electrostatic force experienced by any charge.
Answer:
F = 7.68 10¹¹ N, θ = 45º
Explanation:
In this exercise we ask for the net electric force. Let's start by writing the configuration of the charges, the charges of the same sign must be on the diagonal of the cube so that the net force is directed towards the interior of the cube, see in the attached numbering and sign of the charges
The net force is
F_ {net} = F₂₁ + F₂₃ + F₂₄
bold letters indicate vectors. The easiest method to solve this exercise is by using the components of each force.
let's use trigonometry
cos 45 = F₂₄ₓ / F₂₄
sin 45 = F_{24y) / F₂₄
F₂₄ₓ = F₂₄ cos 45
F_{24y} = F₂₄ sin 45
let's do the sum on each axis
X axis
Fₓ = -F₂₁ + F₂₄ₓ
Fₓ = -F₂₁₁ + F₂₄ cos 45
Y axis
F_y = - F₂₃ + F_{24y}
F_y = -F₂₃ + F₂₄ sin 45
They indicate that the magnitude of all charges is the same, therefore
F₂₁ = F₂₃
Let's use Coulomb's law
F₂₁ = k q₁ q₂ / r₁₂²
the distance between the two charges is
r = a
F₂₁ = k q² / a²
we calculate F₂₄
F₂₄ = k q₂ q₄ / r₂₄²
the distance is
r² = a² + a²
r² = 2 a²
we substitute
F₂₄ = k q² / 2 a²
we substitute in the components of the forces
Fx = [tex]- k \frac{q^2}{a^2} + k \frac{q^2}{2 a^2} \ cos 45[/tex]
Fx = [tex]k \frac{q^2}{a^2}[/tex] ( -1 + ½ cos 45)
F_y = k \frac{q^2}{a^2} ( -1 + ½ sin 45)
We calculate
F₀ = 9 10⁹ 4.25² / 0.440²
F₀ = 8.40 10¹¹ N
Fₓ = 8.40 10¹¹ (½ 0.707 - 1)
Fₓ = -5.43 10¹¹ N
remember cos 45 = sin 45
F_y = - 5.43 10¹¹ N
We can give the resultant force in two ways
a) F = Fₓ î + F_y ^j
F = -5.43 10¹¹ (i + j) N
b) In the form of module and angle.
For the module we use the Pythagorean theorem
F = [tex]\sqrt{F_x^2 + F_y^2}[/tex]
F = 5.43 10¹¹ √2
F = 7.68 10¹¹ N
in angle is
θ = 45º
According to Moseley, the properties of elements are a
periodic function of their
Answer:
According to Henry Moseley, Atomic number is the fundamental property of the elements because elements are made up of atoms . ... So the physical and chemical properties of elements are periodic functions of their atomic number.
Current is the movement of positive charges called electrons.
A. True
B. False
help pls <33
Answer:
False -> negative charge
Answer:
false
Explanation: electrons are negative charges
protons are positive charges
A person has power of 550 watt. What does it mean?
Answer:
It means that person can do work or can posses energy at a rate of 550 watts.
Or : can posses energy of 550 joules in one second.
Explanation:
[tex]{ \bf{power = \frac{work}{time} }}[/tex]
An empty cardboard box falls from a high platform. Through the use of special equipment it was found that the energy of the cardboard box at the top of the fall was more than the energy of the box at the bottom of the fall. Explain.
Answer:
The mechanical energy of the cardboard box, M.E. = K.E. + P.E.
Where;
P.E. = The potential energy of the cardboard box = m·g·h
K.E. = The kinetic energy of the cardboard box = (1/2)·m·v²
Where;
m = Mass of the cardboard box
g = The (constant) acceleration due to gravity ≈ 9.81 m/s²
h = The height of the cardboard box
v = The velocity of the cardboard box
At the top of the fall, where h = The height of the platform = [tex]h_{platform}[/tex], and v = 0 (the box is initially at rest at the top), the M.E. is given as follows;
[tex]M.E._{top}[/tex] = P.E. + K.E. = m·g·[tex]h_{platform}[/tex] + (1/2) × m × 0² = m·g·[tex]h_{platform}[/tex]
However, at the bottom of the fall, the height of the box, h = 0, the velocity of the box, v = 0, therefore, the total energy at the bottom, after the box comes to rest, [tex]M.E._{bottom}[/tex] = 0
Therefore;
The total energy of the box at the top of the fall, .[tex]M.E._{top}[/tex] = m·g·[tex]h_{platform}[/tex] was more than the total energy of the box at the bottom of the fall,
[tex]M.E._{bottom}[/tex] = 0
Explanation:
4. An aluminium bar weighs 17 kg in air. How much force is required
to lift the bar while it is immersed in gasoline? The density
of aluminium is 170 kg/m' and that of gasoline is 42 kg/m
Explanation:
1ml = 2.7g
Xml = 1.5g
Divide 1.5 by 2.7 to find X.
Obviously, since 1.5 is less than 2.7, you know the answer will be less than 1.
(it’s .5555555555)
help me with this one
Answer:
Explanation:
2. a
3. c
diffusion in physics
Answer:
sorry but which class your talking 'bout
find the expression for the displacement covered in nth or in last one second
Answer:
Snth = u + a/2 ( 2n - 1)
Explanation:
Do you need explanation based on graph, integration or other method?
A bucket filled woth water seems light while it sinks into water.Also show their relation using formula
Answer: This phenomenon happens due to upthrust exerted by water.
Explanation:
We know that,
Liquid Pressure is directly proportional to the height of the vertical column in the liquid.(P∝h)
When a bucket filled water is sunk into the water container, there occur difference in the pressure in top and bottom of the water container. Due to this, water exerts an upward force on the bucket filled with water. This is called Uprthrust.
Upthrust on the bucket makes the bucket filled with water lose some of it's weight and causes apparent loss in weight.
Hence, the bucket filled with water seems light while it sinks into water.
Muốn đun sôi 200g nước từ 30 độ cần cung cấp nhiệt lượng bao nhiêu :
Answer:
cần cung cấp 70 độ vì nước sôi ở 100°C
Explanation:
Two children (each having a mass of 60 kg) are standing on the edge a merry-go-round (mass of 140 kg) as it spins with an angular velocity of 0.75 rad/s. The two children jump off the merry-go-round. What is the angular velocity of the merry-go-round after the children have jumped off
Answer:
The angular velocity after the children jump off is approximately 1.4 rad/s
Explanation:
The given parameters are;
The masses of each child, m₁, and m₂ = 60 kg
The mass of the merry-go-round, m₃ = 140 kg
The initial angular velocity, [tex]\omega_i[/tex] = 0.75 rad/s
The angular velocity after the children jump off = [tex]\omega_f[/tex]
According to the principle of conservation of angular momentum
The angular momentum = I × ω
The moment of inertia, I = m × R²
The total initial angular momentum = [tex]I_i \times \omega_i = m_i \times R^2 \times \omega_i[/tex]
The total angular momentum after the children jump off = [tex]I_f \times \omega_f = m_f \times R^2 \times \omega_f[/tex]
The initial mass, [tex]m_i[/tex] = m₁ + m₂ + m₃ = 60 kg + 60 kg + 140 kg = 260 kg
The final mass, [tex]m_f[/tex] = m₃ = 140 kg
According to the principle of conservation of linear momentum, we have;
[tex]I_i \times \omega_i[/tex] = [tex]I_f \times \omega_f[/tex]
Therefore;
260 kg × R² × 0.75 rad/s = 140 kg × R² × [tex]\omega_f[/tex]
∴ [tex]\omega _f[/tex] = (260 kg × R² × 0.75 rad/s)/(140 kg × R²) = 1.39285714 rad/s. ≈ 1.4 rad/s
The angular velocity after the children jump off, [tex]\omega _f[/tex] ≈ 1.4 rad/s.
The distance a cart moves down a track (from rest) is proportional to the time squared. How far would a cart move down a track (from rest) in two seconds if it moves (from rest) a distance of 20 cm in one second?
A) 5 cm B) 10 cm C) 20 cm D) 40 cm E) 80 cm
A car move down a track a distance of 80 cm
Letter E 80 cm
Proportional
if the distance is proportional to the time square we can express such condition writing
d = k*t² (1)
where d is the distance t is the time and k is the constant of proportionality.
Now we must considerer that if the cart moves a distance of 20 cm in one second then by substitution in equation (1)
20 = k * (t)² ⇒ 20 = k*1 then k = 20
The proportionality constant is K = 20
To determine how far the cart move down in 2 seconds, again by substitution in equation (1) ( but now knowing k )
d = 20*(2)²
d = 20*4
d = 80 cm
