a. Tr+Tf = 10 s. = Time in air.
Tr = Tf, Tr+Tr = 10, Tr = 5 s. = Rise time.
Y = Yo + g*Tr = 0 @ max ht.
Yo + (-9.8)*5 = 0
Yo = 49 m/s or about 50 m/s.
b. Yo = Vo*sin50 = 49.
Vo = 49/sin50 = 64.0 m/s.
c. Xo = Vo*Cos50 = 64*Cos50 = 41.1 m/s.
Range = Xo*(Tr+Tf) = 41.1 * 10 = 411 m.
d. The range was said to have a lethal
effect at 300 meters, but it didn't say that was the max range.
In 1346 the army of King Edward III of England defeated the forces of King Phillip VI of France at the battle of Crecy.The following passage gives some details:
The main reason for Edward III's success was undoubtedly the longbow. The records say that skilled long bowmen could fire as many as 12 arrows a minute- with up to 3 arrows in the air at the same time. They were said to have a lethal effect at a range of 300m.
A) The time of flight was about 10s. Assuming the path of the arrow was symmetrical show that the initial vertical component of the arrow's velocity was about 50ms-1.
B) If these arrows were fired at 50 degrees to the horizontal, calculate the velocity at which they left the longbow.
c)Show that the theoretical range was about 400m.
d)The range calculated is greater than 300m quoted in the passage. State and explain some possile reasons for the difference in the answers.
PLEASE help in a simple and detaileld way because i am really confused
3 answers
I dont get all these tf, tr, yo terms you used please expain more clearly i dont understant it
Vo = Initial velocity.
Xo = Horizontal component of initial velocity.
Yo = Vertical component of initial velocity.
Tr = Rise time or time to reach max. height.
Tf = Fall time.
Xo = Horizontal component of initial velocity.
Yo = Vertical component of initial velocity.
Tr = Rise time or time to reach max. height.
Tf = Fall time.
1 answer