Physics math URGENT! Need help with problems due soon! PLEASE and THANKS!?

Question

An object with a mass of 100 Kg is dragged up an incline by applying a force F. The total distance moved along the incline is 200 m and the vertical height gained in moving this distance is 20 m. What is the magnitude of the force F if friction is negligible? (Assume g = 10 m/s2)

Also need help with this one PLEASE!

What is the acceleration of an object that slides down an inclined plane that has a gradient of 1:4 (increases in height by 1 m when you travel along the plane 4 m) Ignore friction and assume g = 10 m/s2.

Answer 1

m = 100kg

g = 10m/s²

d = 200m

h = 20m

F = ?

work = potential energy

Fd = mgh

so

F = mgh/d = 100*10*20/200 = 100N

the component of gravity down the plane is gsinθ

you are given tanθ = 1/4

so using pythagoras to find the hypotenuse = √17

you get

sinθ = 1/√17

then

a = gsinθ = 10/√17 = 2.43m/s²

,.,.