Question

please solve immediately and send with proper steps​

Answer 1

I have don,t know

Explanation:

t=6578

Answer 2

Explanation:

r = (4cos2t) i + (4sin2t) j + 6t k

diff wrt t

dr/dt = 4 x 2 (-sin2t) i + 4 x 2 cos2t j + 6 k

= - 8 sin2t i + 8 cos2t j + 6 k

Again diff w.r.t t

d²r/dt² = - 16 cos2t i - 16 sin2t j

acceleration a = d²r/dt² = - 16 cos2t i - 16 sin2t j

At t = π/4

a = -16 x cos π/2 i - 16 x sinπ/2 j

= 0 - 16 x 1 j

= - 16 j

• Magnitude of accln |a| = 16 m/s² (along negative y axis)