Answer:
a) We kindly invite you to see below the Free Body Diagram of the forces acting on the sled.
b) The weight of the sled is 490.35 newtons.
c) A force of 147.105 newtons is needed to start the sled moving.
d) A force of 49.035 newtons is needed to keep the sled moving at a constant velocity.
Explanation:
a) We kindly invite you to see below the Free Body Diagram of the forces acting on the sled. All forces are listed:
- External force exerted on the sled, measured in newtons.
- Friction force, measured in newtons.
- Normal force from the ground on the mass, measured in newtons.
- Weight, measured in newtons.
b) The weight of the sled is determined by the following formula:
(1)
Where:
- Mass, measured in kilograms.
- Gravitational acceleration, measured in meters per square second.
If we know that and
, the weight of the sled is:
The weight of the sled is 490.35 newtons.
c) The minimum force needed to start the sled moving on the horizontal ground is:
(2)
Where:
- Static coefficient of friction, dimensionless.
- Weight of the sled, measured in newtons.
If we know that and
, then the force needed to start the sled moving is:
A force of 147.105 newtons is needed to start the sled moving.
d) The minimum force needed to keep the sled moving at constant velocity is:
(3)
Where is the kinetic coefficient of friction, dimensionless.
If we know that and
, then the force needed to keep the sled moving at a constant velocity is:
A force of 49.035 newtons is needed to keep the sled moving at a constant velocity.
