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(Part 1 of 3)
A boat moves through the water with two forces acting on it. One is a 2.90×103 N forward push by the motor, and the other is a 1.69×103 N resistive force due to the water.
What is the acceleration of the 1177.5 kg boat?
ANSWER: 1.0276
(Part 2 of 3)
If it starts from rest, how far will it move in 17.7 s?
ANSWER: 160.969
(part 3 of 3)
What will be its speed at the end of this time?
ANSWER: unknown

I NEED ANSWER FOR PART 3

Respuesta :

1) [tex]1.028 m/s^2[/tex]

We can solve this part by using Newton's second law:

[tex]F=ma[/tex] (1)

where

F is the net force

m is the mass

a is the acceleration

There are two forces acting on the boat:

[tex]F_1= 2.90 \cdot 10^3 N[/tex] forward

[tex]F_2 = 1.69\cdot 10^3 N[/tex] backward

So the net force is

[tex]F=2.90\cdot 10^3-1.69\cdot 10^3=1.21\cdot 10^3 N[/tex]

We know that the mass of the boat is

m = 1177.5 kg

So we can now use eq.(1) to find the acceleration:

[tex]a=\frac{F}{m}=\frac{1.21\cdot 10^3}{1177.5}=1.028 m/s^2[/tex]

2) 161.0 m

We can solve this part by using the following suvat equation:

[tex]s=ut+\frac{1}{2}at^2[/tex]

where

s is the distance travelled

u is the initial velocity

t is the time

a is the acceleration

Here we have

u = 0 (the boat starts from rest)

[tex]a=1.028 m/s^2[/tex]

Substituting t = 17.7 s, we find the distance covered:

[tex]s=0+\frac{1}{2}(1.028)(17.7)^2=161.0 m[/tex]

3) 18.2 m/s

The speed of the boat can be found with the following suvat equation

[tex]v=u+at[/tex]

where

v is the final velocity

u is the initial velocity

t is the time

a is the acceleration

In this case we have

u = 0 (the boat starts from rest)

[tex]a=1.028 m/s^2[/tex]

And substituting t = 17.7 s, we find the final velocity:

[tex]v=0+(1.028)(17.7)=18.2 m/s[/tex]

And the speed is just the magnitude of the velocity, so 18.2 m/s.