How many degrees are there between the direction of motion and the force of friction?
A. O
B. 270
C. 90
D. 180
The correct option is (d).
Angle should be 180° between the direction of force and the direction of motion of a body as work done is equal to force multiplied by displacement multiplied by cosx.
Friction is a force that opposes motion. When two objects are in contact, friction is acts in a direction opposite to the motion of the object.A force known as friction prevents relative motion between surfaces that are in touch. One of the more basic features of friction is that it always runs parallel to the surfaces with which it makes contact and opposes any motion or attempted motion of the systems with respect to one another.What is the direction of friction force?When a force is applied to stop it from moving, frictional force provides resistance. As a result, it always moves in the opposite direction of an item in motion. Friction acts on the right when force is applied to the left.Learn more about direction of friction force brainly.com/question/24322020
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If you walk up a set of steps empty handed and walk up the same set of steps holding a flower pot in thesame amount of time. Which requires more work?
a.) empty handed b.) holding flower pot c.) same
Explanation:
I think holding a flower pot. more energy will be needed
Aunt Mary needs to hang a picture in her bedroom. She uses a hammer to drive the nail into the wall. Find the force exerted by the hammer on the nail if the hammer stays in contact with the nail for 0.5s and has an impulse of 25Ns
Answer:
50N
Explanation:
Impulse = Force × Time
25 = Force × 0.5
Force = 25/0.5
= 50N
A hydrogen atom has a radius of 2.5 x 10-11 m
Determine the radius of a magnesium atom.
Answer:
[tex]R = 1.5* 10^{-10}m[/tex]
Explanation:
Given
[tex]r = 2.5 * 10^{-11}m[/tex] -- radius of hydrogen atom
See attachment
Required
Determine the radius of magnesium atom (R)
From the attachment, the ratio of a hydrogen atom to a magnesium atom is:
[tex]Ratio = 6mm : 36mm[/tex]
Simplify
[tex]Ratio =1 : 6[/tex]
Represent the radius as ratio:
[tex]Ratio = r : R[/tex]
Substitute [tex]r = 2.5 * 10^{-11}m[/tex]
[tex]Ratio = 2.5 * 10^{-11}m : R[/tex]
Equate both ratios
[tex]2.5 * 10^{-11}m : R = 1 : 6[/tex]
Express as fraction
[tex]\frac{2.5 * 10^{-11}m}{R} = \frac{1}{6}[/tex]
Cross Multiply
[tex]R * 1 = 2.5 * 10^{-11}m * 6[/tex]
[tex]R * 1 = 2.5 * 6* 10^{-11}m[/tex]
[tex]R * 1 = 15* 10^{-11}m[/tex]
[tex]R = 15* 10^{-11}m[/tex]
[tex]R = 1.5*10* 10^{-11}m[/tex]
[tex]R = 1.5* 10^{1-11}m[/tex]
[tex]R = 1.5* 10^{-10}m[/tex]
Hence, the radius of the magnesium atom is: [tex]1.5* 10^{-10}m[/tex]
Rain and wind place which type of load on structures?
A) Dynamic load
B) Soft load
C) Gradual load
D) Static load
which of the following correctly describes the hierarchy of genetic material within a cell
Answer: D- Each chromosome in a cell is made up of two chromatids, which are each made up of molecules of DNA
Explanation:
A macromolecule is a large molecule that is made of many smaller units. Chromosomes are macromolecules that contain all of the genetic information in a cell. Chromosomes are each made of two smaller units called chromatids. Chromatids are each made up of molecules of DNA. Therefore, the correct description of the hierarchy of genetic material in a cell is that each chromosome in a cell is made up of two chromatids, which are each made up of molecules of DNA. The structures become more and more microscopic as one moves down the hierarchy.
How many electrons per second flow through a wire with a 12pA current?
A rock has 750 J of potential energy as it sits on a ledge. If the rock were pushed off the ledge, how much would it have just before it hit the ground?
Answer:
the 750 j will have potential energy is 375
Explanation:
750/2 is 375
Car A has twice the mass of Car B; both travel at the same speed. Compared to Car B. Car A has:
o the same the energy
o four times the energy
Otwice the energy
one-half the energy
one-fourth the energy
Answer:
Car A has twice the energy of car B.
Explanation:
The kinetic energy of an object is given by :
[tex]K=\dfrac{1}{2}mv^2[/tex]
Where
m is the mass
v is the speed of the object
Car A has twice the mass of Car B. Both travel at the same speed i.e.
[tex]m_A=2m_B[/tex]
So,
[tex]\dfrac{K_A}{K_B}=\dfrac{(1/2)m_Av^2}{(1/2)m_Bv^2}\\\\=\dfrac{2m_B}{m_B}\\\\\dfrac{K_A}{K_B}=2\\\\K_A=2\times K_B[/tex]
So, the kinetic energy of car A is twice of the kinetic energy of car B.
Answer:
Car A has twice the energy
Explanation:
An object accelerates at 50 m/s/s with a force of 100 N. What is its mass?
Answer:
Explanation:
A change in an object’s motion—such as Xander speeding up on his scooter—is called acceleration. Acceleration occurs whenever an object is acted upon by an unbalanced force. The greater the net force acting on the object, the greater its acceleration will be, but the mass of the object also affects its acceleration. The smaller its mass is, the greater its acceleration for a given amount of force. Newton’s second law of motion summarizes these relationships. According to this law, the acceleration of an object equals the net force acting on it divided by its mass. This can be represented by the equation:
Acceleration=Netforce-Mass or a=F/m
What are forces? (Check all that apply)
-Push or pull
-An action that has the ability to change potion
-Actions that can increase or decrease the speed of a moving object
-Actions that can change the direction in which an object is moving
-Gravity
-Electromagnetic
-Strong Nuclear Force
-Weak Force
-Matter
Answer:
Push or Pull
Gravity
Strong Nuclear Force
Weak Force
Explanation:
The illustration shows the forces in Newtons (N) acting on three different blocks. Which
boxes will move under these conditions?
Answer:a
Explanation:because I know
Answer:
B & C
Explanation:
the first block will not move
the breakdown of rocks by chemical action of air and water is called
Answer:
Chemical weathering
Explanation:
This changes the molecular structure of rocks and soil. For instance, carbon dioxide from the air or soil sometimes combines with water in a process called carbonation. This produces a weak acid, called carbonic acid, that can dissolve rock.
A 15 n net force is used to move a 5kg box. What is the resulting acceleration?
A. 15m/s^2
B. 5m/s^2
C. 20m/s^2
D. 3m/s^2
Answer:3 m/s
Explanation:
The resulting acceleration to move the 5Kg box is equal to 3m/s². Therefore, option (D) s correct.
What is acceleration?Acceleration can be defined as the rate of change in the velocity of an object with respect to time. The acceleration of an object is a vector parameter with both magnitude and direction. Acceleration is also defined as the first derivative of the velocity w.r.t. time and the second derivative of position w.r.t. time and
According to Newton's 2nd law of motion, the force is equal to the product of the mass (m) and acceleration.
F = ma
And, a = F/m
Therefore, the acceleration (a) inversely proportional to the mass (m).
Given, the force used to move the box, F = 15 N
The mass of the given Box, m = 5 Kg
The resulting acceleration, a = 15/5 = 3 m/s²
Therefore, the acceleration of the box is equal to 3 m/s² when it is pushed with a force of 15 N.
Learn more about acceleration, here:
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A 0.225 kg sample of tin initially at 97.5°c is dropped into 0.115 kg of water. the initial temperature of the water is 10.0°c. if the specific heat capacity of tin is 230 j/kg • °c, what is the final equilibrium temperature of the tin-water mixture
Answer:
The final equilibrium temperature of the tin-water mixture is approximately 18.468 °C
Explanation:
The parameters of heat energy transfer from the tin to the water are given as follows;
The mass of the sample of tin, m₁ = 0.225 kg
The initial temperature of the tin, T₁ = 97.5 °C
The mass of the water into which the tin is dropped, m₂ = 0.115 kg
The initial temperature of the water, T₂ = 10.0 °C
The specific heat capacity of tin, c₁ = 230 J/(kg·°C)
The specific heat capacity of water, c₂ = 4,200 J/(kg·°C)
Let 'T' represent the final equilibrium temperature of the tin-water mixture, we have;
The heat lost by the tin, ΔQ[tex]_{tin}[/tex] = The heat gained by the water ΔQ[tex]_{water}[/tex]
∴ ΔQ[tex]_{tin}[/tex] = ΔQ[tex]_{water}[/tex]
Where;
ΔQ[tex]_{tin}[/tex] = m₁·c₁·(T₁ - T)
ΔQ[tex]_{water}[/tex] = m₂·c₂·(T - T₂)
By substitution, we have;
ΔQ[tex]_{tin}[/tex] = 0.225 kg × 230 J/(kg·°C) × (97.5°C - T)
ΔQ[tex]_{water}[/tex] = 0.115 kg × 4,200 J/(kg·°C) × (T - 10.0°C)
From ΔQ[tex]_{tin}[/tex] = ΔQ[tex]_{water}[/tex], we have;
0.225 kg × 230 J/(kg·°C) × (97.5°C - T) = 0.115 kg × 4,200 J/(kg·°C) × (T - 10.0°C)
∴ 5,045.625 J - 51.75 J/°C × T = 483 J/°C × T - 4,830 J
5,045.625 J + 4,830 J = 534.75 J/°C × T
∴ 534.75 J/°C × T = 9,875.625 J
T = 9,875.625 J/(534.75 J/°C) = 18.4677419 °C ≈ 18.468 °C
The final equilibrium temperature of the tin-water mixture, T ≈ 18.468 °C.