Presentation Transcript
Forces :Forces Tom Wai
Jacky Lu 9E
What is Weight & Mass? :What is Weight & Mass? Weight is cause by the gravitational attraction. The heaviness of an object, change if gravity if different. Measured in Newton. Mass is cause by how many matters are there. The heaviness of an object, it’s the same everywhere. Measured in kilograms.
: Earth 625g Weight 6.25N Mass Mass 6.27N 1.04N Weight 0.625kg 9.2kg 70N 42kg 420N 42kg 9.2kg 1.62N Moon Therefore, mass wouldn’t change in moon, but weight
would change in the moon to 1/6 of the earth.
The 4 main forces :The 4 main forces
Friction :Friction Friction mean the rubbing between two object.
Air Resistance when things is trying to go to a direction in a very fast speed, the rubbing between and the object is causing the air resistance.
Streamlining is mean the shape of an object that is smooth, not too much of angle but in layers, this can make sure that the object can make less friction.
Speed, distance and Time :Speed, distance and Time Distance = time x speed
Speed = Distance/time
Time = Distance/speed 3.13km 8386m 13.03km 5.87km 6458m To find the average total time:
3130+8386+13030+5.87+6458
=36874
36874/600=6154.6
So, the total time is 6155 mins, that’s about 62.5 hrs. 600m/min
: . Distance 50km/h 90km/h 350km 225km 60km Speed Time 5hr 70km/h 4.5hr 40mins Distance = time x speed
Speed = Distance/time
Time = Distance/speed
Moment :Moment Moment is like a torque X 25 15cm 20 25 X 15 =375
375/20=18.75
X=18.75