Mechanics Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

Define acceleration.

A

The rate of change of velocity, a vector quantity.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Define braking distance.

A

The distancec travelled by a vehicle from the time when the breaks are applied to when the vehicle stops.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Define centre of gravity.

A

An imaginary point at which the entire weight of an object appears to act.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Define centre of mass.

A

A point through which any externally applied force produces straight-line
motion but no rotation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Define closed system.

A

An isolated system that has no interaction with its surroundings.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Define displacement.

A

The distance travelled in a particular direction, a vector quentity.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Define drag force.

A

The resistive force exerted by a fluid on an object moving through it.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Define energy.

A

The capacity for doing work, a scalar quantity.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Define equilibrium.

A

A body is in equilibrium when the net force and net moment acting on it are zero.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Define free fall.

A

The motion of an object accelerating under gravity with no other force acting on it.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Define impulse.

A

The product of force and the time for which the
force acts.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Define inelastic collision.

A

A collision in which kinetic energy is lost.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Define instantaneous speed.

A

The speed at the moment it is measured — speed over an infinitesimal
interval of time.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Define kinetic energy.

A

The energy associated with an object as a result of its motion.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Define linear momentum.

A

The product of mass and
velocity of an object- a vector quantity.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Define moment.

A

The product of force and perpendicular distance from a pivot or stated point.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

State Newton’s first law of motion.

A

A body will remain at rest or continue to move with constant
velocity unless acted upon by a resultant force.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

State Newton’s second law of motion.

A

The rate of change of momentum of an object is directly
proportional to the resultant force and takes place in the direction of the force.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

State Newton’s third law of motion.

A

When two objects interact, each exerts an equal but opposite
force on the other during the interaction.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Define normal contact force.

A

The force exerted by a surface on an object, which acts perpendicularly to
the surface.

21
Q

Define power.

A

The rate of work done.

22
Q

Define pressure.

A

The force exerted per unit cross-sectional area.

23
Q

State the principle of conservation of energy.

A

The total energy of a closed system remains constant.

24
Q

State the principle of conservation of momentum.

A

Total momentum of a closed system remains the constant.

25
Q

State the principle of moments.

A

For a body in rotational equilibrium, the sum of the anticlockwise
moments about a point is equal to the sum of the clockwise moments about the same point.

26
Q

Define stopping distance.

A

The total distance travelled from the time when a driver first sees a reason to stop to the time when the vehicle stops, the sum of the thinking distance and the braking
distance.

27
Q

Define terminal velocity.

A

The constant speed reached by an object when the drag force (and upthrust) is equal and opposite to the weight of the object.

28
Q

Define thinking distance.

A

The distance travelled by a vehicle from when the driver first perceives a
need to stop to when the brakes are applied.

29
Q

Define torque (of a couple).

Specifically torque of a couple.

A

The product of one of the forces of a couple and the perpendicular distance between the forces.

30
Q

Define upthrust.

A

The upward buoyant force exerted on a body immersed in a fluid.

31
Q

Define velocity.

A

A vector quantity equal to the rate of change of displacement.

32
Q

Define weight.

A

The gravitational force on an object.

33
Q

Define work.

A

The product of force and the distance moved in the direction of the force.

(Transfer of energy)

34
Q

Define couple.

In the context of forces and moments.

A

A pair of equal and opposite forces acting on a body but not in the same straight line.

35
Q

Define the unit N.

A

1 Newton is the force that would accelerate a 1kg object at 1 m/s^2

36
Q

Define average velocity.

A

Displacement divided by change in time.

37
Q

Define average acceleration.

A

Change in velocity divided by change in time.

38
Q

What quantity is represented by the area under a velocity-time graph?

A

Displacement.

39
Q

What quantity is represented by the area under an acceleration-time graph?

A

Change in velocity.

40
Q

What quantity is represented by the area under a force-time graph?

A

Impulse.

41
Q

What quantity is represented by the area under a force-distance graph?

A

Work.

42
Q

Define tension.

A

The pulling force exerted by a string, cable, or chain on an object.

43
Q

Define density.

A

Mass per unit volume.

44
Q

Define gravitational potential energy.

A

The energy associated with an object as a result of its position in a gravitational field.

45
Q

Define efficiency.

A

The ratio of useful output energy to input energy.

46
Q

Define elastic collision.

A

A collision in which no kinetic energy is lost.

47
Q

Define the unit Joule.

A

1 Joule is the energy transferred when a force of 1 N is applied over a distance of 1 m.

48
Q

State Archimedes’ principle

A

The upthrust exerted on a body by the fluid that the body is immersed in (both fully and partially) is equal to the weight of fluid that the body displaces.

49
Q

Define fluid.

A

A substance that can flow.