Under the influence of a force, an object of mass 4 kg
accelerates from 3 m/s to 6 m/s in 8 s. How much work
was done on the object during this time?

53.3J

Explanation:

Given parameters:

Mass of object  = 4kg

Initial velocity  = 3m/s

Final velocity  = 6m/s

time taken  = 8s

Unknown:

Amount of work done on body = ?

Solution:

Work done is the force applied to move a body through a particular distance.

                     Work done  = force x distance

let us find force and distance:

Using newton's second law of motion:

         F = ma

where m is the mass and a is the acceleration

First find the acceleration;

 Acceleration  =

          V is the initial velocity

           U is the final velocity

   Input the parameters;

      a  =  = 0.38m/s²

     F  = 4 x 0.38  = 1.5N

To find the distance;

  V²  = U²  + 2as

 where s is the distance

         6²  = 3²  + 2(0.38)s

      s  = 35.5m

Work done   = 1.5 x 35.5  = 53.3J

gpe = mass x gravity constant x height or… gpe = mgh

where… mass: measured in kilograms (kg)

gravity: gravity constant on earth = 10.00 m/s2

height: measured in meters (m)

gpe: measured in joules (j) or kilojoules (kj)

how do you solve gpe?

gravitational potential energy (gpe) is the energy an object has because of its position above the. ground.

gpe = mass x gravity constant x height or… gpe = mgh.

mass:

note: to earn full marks when solving science word problems, you must show your work:

formula.

example:

given values:

mass = 0.3 kg.

weight of the box is given as

here this is placed on the inclined of angle 42 degree

now this weight will have two components one is along the incline other is perpendicular to it

so here we need to apply a force parallel to incline opposite to its component of weight

so here the component of weight is given as

here we have

so it requires 75 n force to move it upwards