Motion on Earth and Space Flashcards
To find the average speed of an object
Divide the total distance travelled by the time taken to travel the distance
On a distance time graph, a horizontal line means…
that the objects is not moving (stationary)
On a distance time graph a diagonal straight line means
That the object is moving with constant speed
On a distance time graph a steeper line means
faster speed
A curved line on a distance time graph means
that an object is speeding up or slowing down
Relative speed is
The difference in speed between two moving objects
If car A travels at 10m/s and car B overtakes them at 15m/s, what is the relative speed between car A and B
15m/s minus 10m/s = 5m/s relative speed
Weight is the force of _________ acting on a mass
gravity
Balanced forces mean
the forces acting on a object are equal in size but opposite in direction
If forces are unequal in size but act in opposite directions they are called ____________
Unbalanced forces
Friction always acts in this direction
opposite to the direction of travel. It opposes motion
Examples of drag force
friction, air resistance, water resistance
Define streamlined
a way of changing the shape of an object to reduce drag forces from air or water
If an object has balanced forces it’s motion will be
Constant, either not moving or a constant speed
If an object has unbalanced forces acting it’s motion will be
Changing speed, speeding up or slowing down
Forces can be represented by these
Arrows, The size of the arrow tells us the size of the force
The Earth takes this long to spin on it’s axis once
24 hours
The Earth takes this long to travel once around the Sun
365.25 days
Why do we have a leap year
A year is 365 days but it takes 365.25 days to travel around the Sun. Every 4 years we add a day to account for the extra quarter of a day
Why do we have seasons?
The Earths axis is tilted at 23 degrees. In summer we are tilted toward the Sun. In winter we are tilted away
When we have summer, what are people in the Southern Hemisphere (Australia) having
Winter
The Moon takes this long to go around the Earth
28 days
We see the moon because
It reflects the Sun’s light toward us
The forces that makes the Earth go around the Sun and the Moon go around the earth
Gravity
