Question

Could you please show your work as well? Thank you!

Answer 1

Solution a)

When the fish is pulled out at constant speed means that all the forces acting on the fish has a resultant =0N

This is because if an object experiences any external force it moves with an acceleration so no acceleration means no resultant force.

Now, there are only two forces acting on the string.

First, is the weight of the fish.

Second, is the force at which the line pulls up the fish.

The second force should be working in opposite direction in order to pull the fish up.

We know,

$F_{total}=0$

$\Rightarrow W_{fish}-F_{line}=0$

$\Rightarrow F_{line}= W_{fish}$

$\Rightarrow W_{fish}= 65N$

So, at constant speed the heaviest weight the tie could pull is 65N.

Solution b)

If the fish is pulled out at the speed of 1.2ms^-2

Here, as the fish is pulled up with an acceleration.

From the figure,

m is the mass of the fish =Weight of the fish/ g

a is total acceleration of the fish=1.2ms^-2

g is acceleration due to gravity =9.8ms^-2

$F_{ext} =ma$

$\Rightarrow F_{line} -W_{fish}= ma$

$\Rightarrow F_{line} =W_{fish}+ \frac{W_{fish}}{g}a$

$\Rightarrow F_{line} =W_{fish}\left (1+ \frac{a}{g} \right )$

$\Rightarrow W_{fish} =\frac{F_{line}}{\left (1+ \frac{a}{g} \right )}$

$\Rightarrow W_{fish} =\frac{65}{\left (1+ \frac{1.2}{9.8} \right )}$

$\therefore W_{fish} \approx 58N$

So, the heaviest weight it could pull is 58N