Dynamics In Space Flashcards
What is the definition of “speed”?
The distance travelled per second
What is the distance travelled per second?
Speed
What is the unit of speed?
ms^-1
What is the unit ms^-1 for?
Speed
What are the two types of speed?
Average and Instantaneous
What is “average speed”?
Speed calculated over a long time interval
What do you call speed calculated over a long time interval?
Average speed
What is “instantaneous speed”?
Speed at an instant time, calculated over a short period of time?
What do you call speed at an instant time?
Instantaneous speed
What is the equation for average speed?
v = d / t
What two groups can physical quantities be divided into?
Vectors and Scalars
What is a “vector”?
A vector is a physical quantity that can be completely described by stating magnitude and direction
What physical quantity can be completely described by stating magnitude AND direction?
Vectors
What is a “scalar”?
A scalar is a physical quantity that can be completely described by stating it’s magnitude only
What is magnitude?
Size
What do you call size?
Magnitude
Give three examples of a scalar
- Distance
- Speed
- Mass
- Time
- Energy
Give three examples of a vector
- Displacement
- Velocity
- Force
- Acceleration
What is “velocity”?
Velocity is defined as the displacement of an object per second.
What do you call the displacement of an object per second?
Velocity
What is “acceleration”?
Acceleration is the change in velocity per second. It’s measured in metres per second per second (ms^-2).
What do you call the change in velocity per second?
Acceleration
What is the unit for acceleration?
ms^-2
What is the unit ms^-2 for?
Acceleration
What is the formula for acceleration?
a = v - u / t
What is the formula “a = v - u / t” used for?
Acceleration
What is a “force”?
A force is a push or a pull.
What do you call a push or a pull/
Force
What is the only was a force can be detected?
Forces can only be detected by their effects on an object.
What can forces change?
Forces can change an object’s;-
• direction
• speed
• shape
What is force measured in?
Newtons (N)
What is the unit Newtons (N) used for?
Force
What is “weight”?
Weight is the downwards gravitational force that acts on a mass
What do you call the downwards gravitational force that acts on a mass?
Weight
What is “gravitational field strength”?
Gravitational Field Strength is the weight per kilogram of mass.
What is the gravitational field strength on Earth?
9.8Nkg^-1
What is the equation for weight?
W = m g
What is the equation “W = m g” used for?
Weight
What is “friction”?
Friction is a resisting force that opposes the motion of an object. It’s caused by 2 objects rubbing together.
• Friction can slow down and/or stop the motion of an object.
• Friction can cause grip.
• Heat is generated from friction
