Newtons Second Law of Motion - Worksheet | Distance Learning ... - Free Printable

Let’s solve each question one by one, step by step.

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Q.10: What is the acceleration of the car?

We are told:
- Mass of the toy car = 20 kg
- Force F₁ = 50 N to the left (←)
- Force F₂ = 20 N to the right (→)

Since forces are in opposite directions, we find the net force by subtracting them:

Net force = F₁ - F₂ = 50 N - 20 N = 30 N to the left

Now use Newton’s Second Law:
Force = mass × acceleration → so acceleration = Force / mass

Acceleration = 30 N / 20 kg = 1.5 m/s²

✔ So the answer is a) 1.5 m/s²

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Q.11: Isaac Newton’s second law of motion is also known as the law of _________.

Newton’s three laws:

1st law → Law of Inertia
2nd law → F = ma → relates force, mass, and acceleration
3rd law → Action-Reaction

So the second law is about how force causes acceleration.

✔ Answer is d) acceleration

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Q.12: A box with mass 2 kg accelerates 5 m/s² to the East. Forces applied: F₁ = 30 N East, F₂ = 40 N West, and an Unknown Force (also pointing East). Find the unknown force.

First, let’s figure out what net force is needed to cause this acceleration.

Use F_net = mass × acceleration
F_net = 2 kg × 5 m/s² = 10 N to the East

Now look at the forces:

- F₁ = 30 N → East (+)
- F₂ = 40 N → West (-)
- Unknown Force = ? → East (+) [since arrow points East]

Let’s call the unknown force “X” (in Newtons, East direction).

Total net force = F₁ + X - F₂
= 30 + X - 40
= X - 10

But we know net force must be 10 N East, so:

X - 10 = 10
→ X = 20 N

✔ So the unknown force is 20 N

Answer is b) 20 N

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Final Answer:
Q.10: a) 1.5 m/s²
Q.11: d) acceleration
Q.12: b) 20 N