Force and Kinematics -- Accelerating a 10kg box vertically

[theanswer2physicsisu]

Homework Statement

How much force is required to lift a 10 kg box such that it is accelerated from rest to a velocity of 5 m/s within 1 second?

Relevant Equations

F = ma ; v/t = a; Kinematics; Force Equations

I realize that there is a downward force of gravity weighing the object toward earth’s surface, equaling F = mg (downward). The upward force would have to be something at least as much as the downward force in order to lift the object up ”such that it is accelerated from rest to a velocity of 5 m/s within 1 second” as stated in the question stem. The remaining question is how much more Newtons (N) of force is required in order to lift the object up at that acceleration in that amount of time?

 

[Orodruin]

What forces act on the box? Which ones do you know? What acceleration is needed? What does Newton’s second law tell you?

 

[theanswer2physicsisu]

What forces act on the box? Which ones do you know? What acceleration is needed? What does Newton’s second law tell you?

Gravitation force downward, lifting force upward, gravitation acceleration is around 9.8 m/s^2, and the acceleration might be calculated via: (Vf-Vi)/t = (5m/s-0m/s)/1s = 5m/s^2. This acceleration of 5 m/s^2 may be plugged into the force equation of F = ma. Newton’s 2nd law tells us a net force acting on an object causes change in object’s motion inversely proportional to mass and directly proportional to the net force acting on the object, sigmaF= ma

 

[Orodruin]

Gravitation force downward, lifting force upward, gravitation acceleration is around 9.8 m/s^2, and the acceleration might be calculated via: (Vf-Vi)/t = (5m/s-0m/s)/1s = 5m/s^2. This acceleration of 5 m/s^2 may be plugged into the force equation of F = ma. Newton’s 2nd law tells us a net force acting on an object causes change in object’s motion inversely proportional to mass and directly proportional to the net force acting on the object, sigmaF= ma

... and therefore ...

 

[theanswer2physicsisu]

... and therefore ...

Therefore what

 

[Orodruin]

With that information you just need to piece the things together. You have stated which forces act on the box, you know what the gravitational force is, you know what the mass is, you know what the acceleration is and you know that ma is the sum of the forces.