Quick Check (2 Viewers)

[azureus88]

Glenn the bowler runs in to bowl and releases the ball 2.4m above the ground with speed 144km/h at an angle of 7 degrees below the horizontal. Take the origin to be the point where the ball is released and take g = 10m/s^2

Show that the coordinates of the ball t seconds after its initial release are given by x =40tcos7 y = 2.4 - 40tsin7 - 5t^2.

Im just wondering whether this question is incorrect or not cause i reckon its meant to be x =144tcos7 y = 2.4 - 144tsin7 - 5t^2.

 

[independantz]

Glenn the bowler runs in to bowl and releases the ball 2.4m above the ground with speed 144km/h at an angle of 7 degrees below the horizontal. Take the origin to be the point where the ball is released and take g = 10m/s^2

Show that the coordinates of the ball t seconds after its initial release are given by x =40tcos7 y = 2.4 - 40tsin7 - 5t^2.

Im just wondering whether this question is incorrect or not cause i reckon its meant to be x =144tcos7 y = 2.4 - 144tsin7 - 5t^2.

You probably forgot to change the speed into ms^-1
y''(let the' indicate the . on top)=-g
y'=-gt+40sin7
y=-5gt+40tsin7+2.4

x''=0
x'=40cos7
x'=40tcos7

 

[azureus88]

yeh i did, thanks for reminding me