M2 Power help please! +rep

14

I'm really not very good at this chapter!
I have done art (i) but unsure what to do for (ii) and (iii)

A supertanker of mass 4x10^8kg is steaming at a constant speed of 8m/s. The resistance force is 2x10^6 N.
(i) What power are the ships engines producing? 1.6x10^7

One of the ships engines suddenly fails but the other continues to work at the same rate.
(ii) Find the deceleration of the ship immediately after the failure.

The resistance force is directly proportional to the speed of the ship.
(iii) Find the eventual steady speed of the ship under one engine only, assuming that the single engine maintains constant power output.

+rep for help

thanks :smile:

Reply 1

steve2005

17

jenny28

I'm really not very good at this chapter!
I have done art (i) but unsure what to do for (ii) and (iii)

A supertanker of mass 4x10^8kg is steaming at a constant speed of 8m/s. The resistance force is 2x10^6 N.
(i) What power are the ships engines producing? 1.6x10^7

One of the ships engines suddenly fails but the other continues to work at the same rate.
(ii) Find the deceleration of the ship immediately after the failure.

The resistance force is directly proportional to the speed of the ship.
(iii) Find the eventual steady speed of the ship under one engine only, assuming that the single engine maintains constant power output.

+rep for help

thanks :smile:

For part (ii) are we to assume the ship has two engines? Your wording implies more than one but it could be 3 engines or more.

Edit: It says other - so must have two engines

Reply 2

rbnphlp

11

jenny28

I'm really not very good at this chapter!
I have done art (i) but unsure what to do for (ii) and (iii)

A supertanker of mass 4x10^8kg is steaming at a constant speed of 8m/s. The resistance force is 2x10^6 N.
(i) What power are the ships engines producing? 1.6x10^7

One of the ships engines suddenly fails but the other continues to work at the same rate.
(ii) Find the deceleration of the ship immediately after the failure.

The resistance force is directly proportional to the speed of the ship.
(iii) Find the eventual steady speed of the ship under one engine only, assuming that the single engine maintains constant power output.

+rep for help

thanks :smile:

For (2)
I think you assume both engines together produce the power required in part (1) so divide 1.6*10^7/2 which is the power of the engine working.then divide by 8ms^-1 to find the force which 1*10^6N

So the force you need is 1*10^6-(2*10^6)=
then you should be able to find the decelaration using F=ma

Reply 3

aramis8

12

Any help with part (iii) please?

Reply 4

Gauthmath_Jenny

9

Reply 5

old_engineer

11

A few points:
1) This thread is 11 years old;
2) Please observe the posting guidelines (hints not full solutions), and remove your full solution;
3) Nice handwriting.

Reply 6

Gauthmath_Jenny

9

Sorry that I didn't notice. Thanks for the reminder. I've removed my solution.

Reply 7

Thanks for not removing the solution

M2 Power help please! +rep

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