Centripetal Forces +

Question 1

centripetal force equation

Answer 1

F = mv2/r could also be a negative?

Question 2

Explain how centrifugal force acts in the washing machine?

Answer 2

A washing machine is basically a spinning top device; thus, when the machine rotates, the centrifugal force balances itself from both sides. When the force exerted by one side of the machine passes through the centre of the machine to act on the other side, a centrifugal force transits into a centripetal force. Therefore, it can be considered as an example of both centripetal and centrifugal force as it totally hangs on its relationship with the centre of the machine.

Question 3

What is a Centrifuge?

Answer 3

A centrifuge is a machine that uses centrifugal force to detach or separate the contents based on their density. A strong centrifugal force is produced by a centrifuge when it spins, which results in the separation of contents. Centrifuge machine delivers speedy results for laboratory and other applications.

Question 4

Define Centrifugation

Answer 4

The process of concentrating and accelerating the particles of different densities for their separation is termed as centrifugation. This process helps to accelerate the natural process of separation. Either filtration or sedimentation method can be used for centrifugation.

Question 5

Centrifugation is affected by these four factors

Answer 5

The density of the samples and solution
Temperature and viscosity of the solution
The distance at which the particles are displaced
Speed of rotation of the device

Question 6

Centripetal force is the force acting towards the _____ of the circular path.

Answer 6

The centripetal force is the force acting towards the centre of the circular path.

Question 7

Turning a car is an example of _______.

Answer 7

Turning a car is an example of centripetal force. Due to the friction between the road and tires, the centripetal force causes the car to turn in a circular path.

Question 8

Acceleration is the change in _____.

Answer 8

Acceleration is the change in velocity

Question 9

The unit of centripetal acceleration is ______.

Answer 9

The unit of centripetal acceleration is m.s^-2.

Question 10

Gravitation is the main force for the planets to orbit around the Sun.

Answer 10

Gravity is responsible for the motion of planets around the Sun.

Question 11

Uniform circular motion

Answer 11

the motion of an object moving along a circular path at a
constant speed

Question 12

angular displacement

Answer 12

Angular displacement q indicates the angle through which an object has rotated. It is measured in radians

Question 13

A radian

Answer 13

A radian is an angle, equal to just under 60 degrees

Question 14

Average angular velocity

Answer 14

Average angular velocity (w) is angular displacement divided by the time interval over which that angular displacement occurred. It is measured in rad/s.

Question 15

Instantaneous angular velocity

Answer 15

Instantaneous angular velocity is how fast an object is rotating at a specific moment in time.

Question 16

Angular acceleration

Answer 16

Angular acceleration a tells how much an object’s angular speed changes in one second. It is measured in rad/s per second.

Question 17

When an object moves in a circle, it has an acceleration directed toward the center of the
circle.

Answer 17

true

Question 18

The amount of gravitational field depends on two things: the mass of the planet creating the field (M) and the distance you are from that planet’s center (d).

Answer 18

true

Question 19

The weight of an object—that is, the gravitational force of a planet on that object is defined as ______

Answer 19

mg

Question 20

Gravitational mass indicates how an object responds to a gravitational field.

Answer 20

true

Question 21

Inertial mass indicates how an object accelerates in response to a net force

Answer 21

true

Question 22

In every experiment ever conducted, an object’s gravitational mass is equal to its inertial
mass.

Answer 22

true

Question 23

For objects moving in circular paths, you can characterize their motion around the circle in terms of frequency (f)
and period (T). The frequency is the number of revolutions the object makes in a second (1/s, Hz). The period is the
time it takes to complete one revolution. The period and frequency are expressed as: f = 1/ 𝑇
and T = 1/𝑓
.

Answer 23

true

Question 24

When objects are manipulated into vertical circular paths, we need to account for the force of gravity, or weight (mg) of the object during certain points along the circle. Always, draw a FBD and sum the forces to avoid careless mistakes.

Answer 24

true

Question 25

Work done by a steady force?

Answer 25

The amount of force multiplied by the distance an object moves
parallel to that force: W = F x cos (θ)

Question 26

Joule

Answer 26

Newtons x meters

Question 27

positive work

Answer 27

is done by a force parallel to an object’s displacement

Question 28

negative work

Answer 28

is done by a force antiparallel to an object’s displacement.

Question 29

Is work a vector ro scalar?

Answer 29

Work is a scalar quantity so it can be positive or negative, but does not have a direction.

Question 30

What is the area under a force-displacement graph?

Answer 30

work

Question 31

Kinetic Energy

Answer 31

KE = ½mv2

Question 32

KE = ½mv2, what is m and what is v?

Answer 32

m is the mass of the object, and v is its speed.

Question 33

gravitational potential energy

Answer 33

PEg = mgh (or Ug)

Question 34

PEg = mgh (or Ug), what is m, g, and h?

Answer 34

m is the mass of the object, g is the gravitational field, and h is the vertical height of the object above its lowest position

Question 35

Spring Potential Energy

Answer 35

PE = ½kx2 (or Ue)

Question 36

PE = ½kx2 (or Ue), what is k and x?

Answer 36

Here, k is the spring constant (𝑁/𝑚 ), and x is the distance the spring is stretched or compressed from its equilibrium position.

Question 37

mechanical energy

Answer 37

The term mechanical energy refers to the sum of a system’s kinetic and potential energy.

Question 38

Hooke’s Law

Answer 38

states that the more a s spring is compressed (or stretched) the more force it applies to restore itself to equilibrium. This is expressed as Fs = kx.

Question 39

A “conservative” force (e.g., gravity, spring) converts potential energy to other forms of mechanical energy when it does work. Thus, a conservative force does not change the mechanical energy of a system. So the sum of the potential and kinetic energy of the system is constant.

Answer 39

fact

Question 40

A “nonconservative” force (e.g., friction) can change the mechanical energy of a system. For example, the work
done by friction on an object becomes microscopic internal energy, which raises the object’s temperature and reduces
the system’s kinetic energy. The work done by a nonconservative force can be expressed WNC = (ΔKE) + (ΔPE)

Answer 40

fact

Question 41

The work done on an object by a net force equals the change in kinetic energy of the object: W = KEf - KEi. Therefore, doing positive work will result in an increase of kinetic energy. This relationship is called the work-energy theorem.

Answer 41

fact

Question 42

Solving problems using an energy approach is almost always an easier method than using UAM and kinematics. Think about it. Most often, you do not need to know the time, the mass, no need for constant acceleration, and you do not need to know the path the object takes.

Answer 42

fact

Question 43

Power

Answer 43

Power is the rate at which work gets done. It is expressed as Power = 𝑊𝑜𝑟𝑘/𝑡𝑖𝑚𝑒 with units of J/s, which is renamed as
the watt.

Question 44

watt

Answer 44

J/s