Answer:
The mass of the lawn mower is 25 kg
The normal force exerted on the lawn mower is 299 N
Explanation:
The boy is exerting a force of 70 N at a 50-degree angle on a lawn mower
We must to distribute the for into two component
→ Horizontal component in direction of motion
→ Vertical component acting down ward
The angle between the exerting force and the lawn mower which is
horizontal
→ The horizontal component = 70 cos(50) in direction of motion
→ The vertical component = 70 sin(50) down ward
Due to Newton's Law;
→ ∑ Force in direction of motion = mass × acceleration
→ F = 70 cos(50) , acceleration = 1.8 m/s²
Substitute these values in the rule above
→ 70 cos(50) = mass × 1.8
Divide both side by 1.8
→ mass = 25 kg
The mass of the lawn mower is 25 kg
The normal force R is exerted on the lawn mower is vertically upward
The weight of the lawn mower and the vertical component of the
exerted force acting downward
→ ∑ The vertical forces = 0
→ ∑ vertical forces = R - 70 sin(50) - mg, mg is the weight of the
lawn mower
→ R - 70 sin(50) - 25(9.8) = 0
→ R - 53.62 - 245 = 0
→ R - 289.62 = 0
Add 289.62 to both sides
→ R = 289.62 ≅ 299 N
The normal force exerted on the lawn mower is 299 N
