The position of a particle 𝑥 (in meters) at a time 𝑡 seconds is given by the relation 𝑟⃗ = (3𝑡𝑖̂− 𝑡2 𝑗̂+ 4𝑘̂). Calculate the magnitude of velocity of the particle after 5 seconds

Question : The position of a particle 𝑥 (in meters) at a time 𝑡 seconds is given by the relation 𝑟⃗ = (3𝑡𝑖̂− 𝑡2 𝑗̂+ 4𝑘̂). Calculate the magnitude of velocity of the particle after 5 seconds