Projectile on horizontal surface

  • #1
210
1

Homework Statement



A particle is projected with a speed of 98 m s−1 at an angle A to the horizontal.
The range of the particle is 940·8 m. Find
(i) the two values of A

The Attempt at a Solution



U = 98cosAi + 98sinAj

i direction

s = ut
940.8 = 98cosAt

j direction

s = ut + (0.5)at[itex]^{2}[/itex]
0= 98sinAt - (0.5)gt[itex]^{2}[/itex]
98sinA = gt/2
t = 20sinA

i direction
940.8 = (20sinA)(98cosA)
94.8 = (2sinAcosA)g
94.8 / g = sin2A



And I end up with a math error. Help please.

Homework Statement





Homework Equations





The Attempt at a Solution

 

Answers and Replies

  • #2
TSny
Homework Helper
Gold Member
13,068
3,393
  • #3
210
1
Ooops, sadly it doesn't solve the problem.

94.08 = 2sinAcosA(9.8)
94.08 / 9.8 = sin2A
9.6 = sin2A

math error
 
  • #4
TSny
Homework Helper
Gold Member
13,068
3,393
94.08 = 2sinAcosA(9.8)

This equation doesn't follow from 940.8 = (20)sinAcosA(98)
 
  • #5
210
1
AHHH!! Stupid error!! Thanks!!
 

Related Threads on Projectile on horizontal surface

Replies
2
Views
1K
Replies
12
Views
3K
  • Last Post
Replies
8
Views
2K
  • Last Post
Replies
3
Views
4K
  • Last Post
Replies
9
Views
3K
  • Last Post
Replies
3
Views
2K
  • Last Post
Replies
8
Views
849
Replies
9
Views
2K
  • Last Post
3
Replies
65
Views
3K
Replies
11
Views
1K
Top