Let’s solve the first problem shown in the image — the one with the 200kg particle on a 40° slope, with a 1500N force applied up the slope.
We are to:
- Label all forces acting on the particle (we’ll describe them since we can’t draw here).
- Calculate the acceleration of the particle.
---
Step 1: Understand the situation
A 200 kg block is on a slope inclined at 40° to horizontal.
A force of 1500 N is applied
up the slope (parallel to it).
We assume no friction unless stated — and this problem doesn’t mention friction, so we’ll assume
no friction.
Forces acting on the particle:
1.
Weight (W) = mass × gravity = 200 kg × 9.8 m/s² = 1960 N → acts straight down.
2.
Normal force (N) → perpendicular to the slope, pushing the block away from the surface.
3.
Applied force (F_app) = 1500 N → up the slope.
4.
Component of weight parallel to slope → pulls the block *down* the slope.
5.
Component of weight perpendicular to slope → balanced by normal force.
Since motion is along the slope, we only care about forces parallel to the slope for acceleration.
---
Step 2: Break weight into components
Weight has two parts relative to the slope:
- Parallel component (pulls block down slope):
W_parallel = mg sin(θ) = 200 × 9.8 × sin(40°)
- Perpendicular component (pressed into slope):
W_perp = mg cos(θ) → but this doesn’t affect motion along slope if no friction.
Calculate W_parallel:
sin(40°) ≈ 0.6428
So,
W_parallel = 200 × 9.8 × 0.6428
= 1960 × 0.6428
≈ 1259.89 N (down the slope)
---
Step 3: Net force along the slope
Applied force is
up the slope: +1500 N
Weight component is
down the slope: -1259.89 N
Net force F_net = 1500 - 1259.89 =
240.11 N (up the slope)
---
Step 4: Use Newton’s Second Law to find acceleration
F_net = m × a
→ a = F_net / m = 240.11 / 200 ≈
1.20055 m/s²
Rounded reasonably:
1.20 m/s²
---
Final Answer:
The acceleration of the particle is
1.20 m/s² up the slope.
Parent Tip: Review the logic above to help your child master the concept of inclined plane worksheet.