pdf short cuts for free falling body

1. amazing, shortcuts for freely falling bodies
height Time (t seconds) Square of time(t2
:
seconds x seconds)
(1/2)g
4.9m 1s 1s2
4.9m/s2
19.6m 2s 4s2
4.9m/s2
44.1m 3s 9s2
4.9m/s2
78.4m 4s 16s2
4.9m/s2
122.5m 5s 25s2
4.9m/s2
176.4m 6s 36s2
4.9m/s2
240.1m 7s 49s2
4.9m/s2
313.6m 8s 64s2
4.9m/s2
To find the height of a freely falling body we multiply the values in the square of time by our (1/2)g ,thus
(1s2
)( 4.9m/s2
)=4.9m,
(4s2
)( 4.9m/s2
)=19.6m
(9s2
)( 4.9m/s2
)=44.1m
(16s2
)( 4.9m/s2
)=78.4m
shortcuts:
(1s2
)( 4.9m/s2
)=4.9m, can be (1s2
)( 5m/s2
)=5m-(0.1s2
)(1m/s2
)=5m-0.1m=4.9m
(4s2
)( 4.9m/s2
)=19.6m can be (4s2
)( 5m/s2
)=20m-(0.4s2
)(1m/s2
)=20m-0.4m=19.6m
(9s2
)( 4.9m/s2
)=44.1m can be (9s2
)( 5m/s2
)=45m-(0.0s2
)(1m/s2
)=45m-0.9m=44.1m
(16s2
)( 4.9m/s2
)=78.4m can be (16s2
)( 5m/s2
)=80m-(1.6s2
)(1m/s2
)=80m-1.6m=78.4m
hint :
for 1second 1 x 5 -0.1= 4.9m
for 2seconds 4 x 5 -0.4= 19.6m
for 3seconds 9 x 5 -0.9= 44.1m
for 4seconds 16 x 5 -1.6= 78.4m