Let's solve each problem step by step using
Newton’s Second Law of Motion, which is:
>
F = m × a
> Where:
> -
F = Force (in Newtons, N)
> -
m = mass (in kilograms, kg)
> -
a = acceleration (in m/s²)
---
1. How much force is needed to accelerate a 1000-kg car at a rate of 3 m/s²?
Use:
F = m × a
= 1000 kg × 3 m/s²
=
3000 N
✔ Answer: 3000 N
---
2. If a 70-kg swimmer pushes a pool wall with a force of 250 N, at what rate will the swimmer accelerate from the wall?
Use:
a = F / m
= 250 N / 70 kg
≈ 3.5714 m/s²
Rounded to 2 decimals:
3.57 m/s²
✔ Answer: 3.57 m/s²
---
3. A weightlifter raises a 200-kg barbell with an acceleration of 3 m/s². How much force does the weightlifter use to raise the barbell?
Use:
F = m × a
= 200 kg × 3 m/s²
=
600 N
✔ Answer: 600 N
---
4. A dancer lifts his partner above his head with an acceleration of 2.5 m/s². The dancer exerts a force of 200 N. What is the mass of the partner?
Use:
m = F / a
= 200 N / 2.5 m/s²
=
80 kg
✔ Answer: 80 kg
---
5. Newton’s second law of motion states that a(n) ________ force acting on an object causes it to accelerate according to the formula net force = mass × acceleration. Which means the acceleration of the object is directly proportional to the ________ and inversely proportional to the mass.
Fill in the blanks:
- First blank:
unbalanced (because balanced forces result in no acceleration)
- Second blank:
force
✔ Answer:
a(n)
unbalanced force
directly proportional to the
force
---
6. The two factors that affect acceleration are:
From Newton’s Second Law:
a = F/m
So, acceleration depends on:
-
Force
-
Mass
✔ Answer: force and
mass
(Other options like speed, distance, weight are not direct factors in the formula.)
---
7. Friction:
a. is
static friction when an object is not moving.
b. is
sliding friction when two objects rub against each other.
i.
Fluid friction – a special type of sliding friction when the object slides through a liquid or gas
c. is
rolling friction when the object rolls over another.
✔ Answers:
a.
static friction
b.
sliding friction
i.
fluid friction
c.
rolling friction
---
✔ Final Answers Summary:
| Question | Answer |
|--------|--------|
| 1 | 3000 N |
| 2 | 3.57 m/s² |
| 3 | 600 N |
| 4 | 80 kg |
| 5 | unbalanced, force |
| 6 | force, mass |
| 7a | static friction |
| 7b | sliding friction |
| 7i | fluid friction |
| 7c | rolling friction |
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Parent Tip: Review the logic above to help your child master the concept of newton s second law of motion worksheet.
