Given :
An 80kg sled rider starts sledding down a 100m hill from rest. If her final velocity is 15m/s.
To Find :
The acceleration down the hill.
The force needed for that kind of acceleration.
Solution :
By equation of motion :

Force required is, F = ma
F = 80×1.125 N
F = 90 N
Hence, this is the required solution.
Answer:
1) 460.5 N
2) 431.7 N
Explanation:
Draw a free body diagram. There are four forces on the hammer:
Applied force 62.5 N in the +x direction, 30 cm from the ground
Reaction force Rᵧ in the +y direction, at the point of contact
Reaction force Rₓ in the +x direction, at the point of contact
Reaction force F at 31° from the vertical, 4.75 cm to the left of the point of contact
Part One
To find F, sum the moments about the point of contact:
∑τ = Iα
(62.5 N) (30 cm) − (F cos 31°) (4.75 cm) = 0
F = 460.5 N
Part Two
To find Rₓ and Rᵧ, sum the forces in the x and y directions.
∑Fₓ = ma
62.5 N − F sin 31° + Rₓ = 0
Rₓ = 174.7 N
∑Fᵧ = ma
-F cos 31° + Rᵧ = 0
Rᵧ = 394.7 N
The net reaction force at the point of contact is:
R = √(Rₓ² + Rᵧ²)
R = 431.7 N
Assuming north as positive direction, the initial and final velocities of the ball are:

(with negative sign since it is due south)

the time taken is

, so the average acceleration of the ball is given by

And the positive sign tells us the direction of the acceleration is north.
Answer:
could you probably expand on the question?
Explanation: