Question

The position of an object of

mass 5 kg as a function of
time is giving by r = (20m/s4)t4
i + (12 m/s3)t3 j. Find the
force acting on the object as a
function of time. Express the
force in unit vectors. Hint:
Remember that Newton's
second Law relates the force
to the acceleration

Answer 1

`F=5(240t^2i+72tj)\ N`

Step-by-step explanation:

Given that,

The mass of the object, m = 5 kg

The position vector is,
`r=20t^4i+12t^3j`

Velocity,
`v=(dr)/(dt)=80t^3i+36t^2j`

Acceleration,
`a=(dv)/(dt)=240t^2i+72tj`

Newton's second law of motion is given as follows:

F = ma

Put all the values,

`F=5(240t^2i+72tj)\ N`

Hence, this is the required solution.