How much lower would a sheep be expected to jump if on a steep upward slope?

[A.T.]

Chickens are more stupid than sheep.

Would something like a scarecrow (fake wolf) prevent sheep from entering an area? Or would they figure out quickly it's fake, if it doesn't move?

 

[Baluncore]

Note to self: Million dollar business idea. Grooming and boarding services for imaginary sheepdogs. Overhead costs: zero!

Inhead costs: Sanity!

 

[sophiecentaur]

Sheep can, without trying, easily do 3 metres in the long jump.

A Haha would tend to take care of that. I expect they are cleverer than I used to think - but they have those whacky eyes . . . . . .

 

[sophiecentaur]

A 1:100 slope would be a lot easier to scale than a 2:1 slope.

Yes, the gradient makes a lot of difference. The point of a Haha or even a shallower structure would mean this effect would be greater, preventing the animal from getting up speed (kinetic energy), to help it. Fact is that the haha is a tried and tested system which has other advantages in that sheep can't spend time damaging a fence when they can't lean on it to feed through it. The fence would be well supported by the top part of the bank.
But we all have our own mental picture of the OP's situation and the best solution would be specific to the actual situation.