The vector position of a particle varies in time according to the expression r(vector)= 9.00 i(with arrow above)− 7.60t2 j(with arrow above) where r(vector) is in meters and t is in seconds.
(a) Find an expression for the velocity of the particle as a function of time. (Use any variable or symbol stated above as necessary.)

v(vector)=_____m/s

Question

The vector position of a particle varies in time according to the expression r(vector)= 9.00 i(with arrow above)− 7.60t2 j(with arrow above) where r(vector) is in meters and t is in seconds.
(a) Find an expression for the velocity of the particle as a function of time. (Use any variable or symbol stated above as necessary.)

v(vector)=_____m/s

anonymous · Answer

got all the other parts correct except this one

anonymous · Answer

=/

anonymous · Answer

v(vector)=-15.2tj(with arrow above)

jamesj · Answer

The velocity vector is the derivative wrt time of the displacement vector.

So v = dr/dt = 0 i + -15.2t j.

The speed is the magnitude of this vector, which for all t > 0 is 15.2t

anonymous · Answer

-15.2 and 15.2 is wrong

anonymous · Answer

i put originally -15.2
and it said it was wrong lol so idk what it is

anonymous · Answer

i forgot the t lol so -15.2 is right

anonymous · Answer

anyone know this?
Calculate the particle's position and velocity at t = 2.00 s.