Question

a particle is moving on x-y plane so that its position vector varies with time as r= 10√3t i^+(10t-t²)j^. If initial velocity of particle is inclined angle Φ from vertical then Φ,is

1) 30° 2) 45° 3) 60° 4) tan-¹(3/4)​

Answer 1

Answer:

Φ from vertical  = 60°

Explanation:

r = 10 √3 t  i   + (10t - t²)j

Velocity = dr/dt

=> Velocity =  10√3i  + (10 - 2t)j

at t = 0 , initial Velocity

=> initial Velocity  = 10√3i  + (10 - 2*0)j

=>initial Velocity  = 10√3i  + 10 j

angle Φ from vertical

=> Tan Φ  =  10√3 /10

=> Tan Φ  = √3

=> Φ = 60°

Φ from vertical  = 60°

Answer 2

Answer:

the answer is 60°.

Explanation:

refer to the above attachment.