As an object falls from rest, its gravitational energy is converted to kinetic energy
G.P.E = K.E = mgh
K.E = (80 Kg)(9.8 m/s²)(30 m)
K.E. = 23,520 J
Answer:

Explanation:
The attached figure shows the whole description. Considering the applied force is 100 N.
The acceleration of both blocks A and B, 
Firstly calculating the mass m using the second law of motion as :
F = ma
m is the mass


m = 125 kg
It suddenly encounters a surface that supplies 25.0 N a friction, F' = 25 N



So, the new acceleration of the block is
. Hence, this is the required solution.
When a car is slowing down, it has a negative acceleration. Although it is not going a negative speed, it is decreasing in velocity, which is the definition of a negative acceleration.
Hope this helps!
Answer:
10.21 N
Explanation:
As the force is a vector, it can be decomposed in two components perpendicular each other, so there is no projection of one component in the direction of the other.
When divided in this way, the magnitude of the resultant vector can be found simply applying trigonometry, as follows:
F² = Fx² + Fy² ⇒ F = √(Fx)²+(Fy)²
Replacing by Fx= 5.17 N and Fy = 8.8 N, we get:
F = √(5.17)²+(8.8)² =10.21 N