To solve for the magnitude of the static friction present between the body and the surface, we need to consider the forces involved and the nature of static friction.
1. Understanding the Problem:
- An external force of 10 N is applied to the body.
- The minimum force required to keep the body in motion is 15 N.
2. Static Friction:
- Static friction is the force that resists the initiation of sliding motion between two surfaces in contact.
- It adjusts itself to be equal and opposite to the applied force, up to a maximum limit.
- The maximum limit of static friction is the force required to overcome static friction and initiate motion.
3. Insight into the Static Friction:
- If an external force of 10 N is applied and the body does not move, the static friction must be exactly 10 N.
- However, the problem specifies that the minimum force required to keep the body in motion is 15 N.
- This implies that the static friction can hold the body stationary until the applied force reaches 15 N.
4. Final Calculation:
- Hence, the maximum magnitude of the static friction is equal to the minimum force required to overcome it.
- Since the minimum force required to keep the body in motion is 15 N, the magnitude of the static friction is:
[tex]\[
\text{Static friction} = 15 \, \text{N}
\][/tex]
Therefore, the magnitude of the static friction present between the body and the surface is 15 N.
