Question

A little girl pushes a 5.0 kg toy baby stroller at constant speed 7.0 m across the floor. She pushes on the handle with a force of 40 N at an angle of 30o with the horizontal. All parts are 4 points each.

Answer 1

Complete Question

1 a A little girl pushes a 5.0 kg toy baby stroller at constant speed 7.0 m across the floor. She pushes on the handle with a force of 40 N at an angle of 30o with the horizontal.  How much work is done by the girl on the wagon?

1b  A farmhand pushes 20 ㎏ bale of hay 4m across the floor of the barn if she exerts a horizontal force of 60 N on the hay, how much work is done? (5 pts)

All parts are 4 points each

Answer:

1a

  $W = 242.5 \ J$

1b

    $W = 240 \ J$

Explanation:

Considering question a

From the question we are told that

       The mass of the toy baby stroller is  $m = 5.0 \ kg$

        The distance covered is    $d = 7.0\ m$

          The force the girl applies on the handle  is  $F = 40 \ N$

          The angle at which this force is applied is  $\theta = 30^o$

Generally the workdone is mathematically represented as

          $W = F_x * d$

Here  $F_x$ is the force along the horizontal axis , this is mathematically represented as

           $F_x = F cos (\theta )$

=>         $F_x = 40 * cos(30 )$

=>         $F_x = 34.64 \ N$

So

              $W = 34.64 * 7$

=>           $W = 242.5 \ J$

Considering question b

From the question we are told that

       The mass of the toy baby stroller is  $m = 20 \ kg$

        The distance covered is    $d = 4 \ m$

          The force the girl applies on the handle  is  $F = 60 \ N$      

Generally the workdone is mathematically represented as

          $W = F * d$

=>     $W = 60 * 4$

=>     $W = 240 \ J$