- #1

- 42

- 0

x = (15.0 m/s)t

y = (2.00 m/s)t - (4.90 m/s2)t2

(a) Write a vector expression for the ball's position as a function of time, using the unit vectors i and j. (Use t, i and j as necessary.)

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- Thread starter ramin86
- Start date

- #1

- 42

- 0

x = (15.0 m/s)t

y = (2.00 m/s)t - (4.90 m/s2)t2

(a) Write a vector expression for the ball's position as a function of time, using the unit vectors i and j. (Use t, i and j as necessary.)

- #2

vsage

Say you have the cartesian point (3,4)

in vector form this is 3i+4j

- #3

- 42

- 0

(a) Write a vector expression for the ball's position as a function of time, using the unit vectors i and j. (Use t, i and j as necessary.)

r = correct check mark m

(b) By taking derivatives, obtain an expression for the velocity vector v as a function of time.

v = correct check mark m/s

(c) By taking derivatives, obtain an expression for the acceleration vector a as a function of time.

a = correct check mark m/s2

Don't get these :

(d) Next use unit vector notation to write an expression for the position of the golf ball at t = 1.20 s.

r(1.20 s) = ( m ) i + ( m ) j

(e) Write an expression for the velocity at this time.

v(1.20 s) = ( m/s ) i + ( m/s ) j

(f) Write an expression for the acceleration at this time.

a(1.20 s) = ( m/s2 ) j

- #4

- 42

- 0

lol nevermind, got them all

- #5

vsage

ramin86 said:

(a) Write a vector expression for the ball's position as a function of time, using the unit vectors i and j. (Use t, i and j as necessary.)Got this one

r = correct check mark m

(b) By taking derivatives, obtain an expression for the velocity vector v as a function of time.Got this one

v = correct check mark m/s

(c) By taking derivatives, obtain an expression for the acceleration vector a as a function of time.Got this one

a = correct check mark m/s2

Don't get these :

(d) Next use unit vector notation to write an expression for the position of the golf ball at t = 1.20 s.

r(1.20 s) = ( m ) i + ( m ) j

(e) Write an expression for the velocity at this time.

v(1.20 s) = ( m/s ) i + ( m/s ) j

(f) Write an expression for the acceleration at this time.

a(1.20 s) = ( m/s2 ) j

I think semantics are messing you up. All they're asking is using the formulae you derived, plug t = 1.20s into each of them: position for d, velocity for e and acceleration for f. Your previous equations should have told you what the i and j components will be at any time t.

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