Case 1
- Mass (m)
- 10kg
- Acceleration (a)
- 9.80665m/s²
98.0665N
Open with these valuesNewton's Second Law Calculator
98.0665N
Result: 98.0665 NMultiply the mass in kilograms by the acceleration in metres per second squared and the force comes out in newtons: 1500 kg at 3 m/s² needs 4500 N. A negative acceleration gives a negative force, which is braking. One newton is one kg·m/s².
The numbers at a glance
Held fixed: Mass (m) 10.000 kg.
| Acceleration (a) (m/s²) | Result (N) |
|---|---|
| 0.00000 | 0.0000 |
| 2.50000 | 25.0000 |
| 5.00000 | 50.0000 |
| 7.50000 | 75.0000 |
| 9.80665Your value | 98.0665 |
| 10.00000 | 100.0000 |
| 12.50000 | 125.0000 |
| 15.00000 | 150.0000 |
| 17.50000 | 175.0000 |
Worked examples
Case 2
- Mass (m)
- 1500kg
- Acceleration (a)
- 3m/s²
4,500.0000N
Open with these valuesCase 3
- Mass (m)
- 0.145kg
- Acceleration (a)
- 20m/s²
2.9000N
Open with these valuesHow it's calculated
F = m × a
- StepEnter the mass of the object in kilograms.
- StepEnter the acceleration in m/s² — use 9.80665 for Earth's gravity.
- ResultRead the net force in newtons; a negative value opposes the motion.
Reference table
| m (kg), a (m/s²) | What it describes | Force (N) |
|---|---|---|
| 1, 1 | One newton, by definition | 1 |
| 2, 0 | No net force, no change in motion | 0 |
| 0.145, 20 | Baseball struck off the bat | 2.9 |
| 10, -3 | 10 kg braking at 3 m/s² | -30 |
| 10, 9.80665 | 10 kg under standard gravity | 98.0665 |
| 1500, 3 | Small car pulling away briskly | 4500 |
Questions
What is Newton's second law?
It states that the net force on an object equals its mass multiplied by its acceleration: F = m × a. For a mass of 10 kg accelerating at 9.80665 m/s², the force is 98.0665 N. It is the law that explains how a force changes an object's motion.
How do I calculate force from mass and acceleration?
Multiply the mass in kilograms by the acceleration in metres per second squared. For 1500 kg at 3 m/s², that is 1500 × 3 = 4500 N. The answer comes out in newtons with no conversion, as long as you use kilograms and m/s².
What is one newton?
One newton is the force that gives a 1 kg mass an acceleration of 1 m/s², so 1 N = 1 kg·m/s². In everyday terms it is roughly the weight of a small apple in your hand. A 10 kg mass under gravity weighs about 98 N.
Is weight the same as force?
Weight is one particular force — the pull gravity exerts on a mass, F = m × g, with g of 9.80665 m/s² on Earth. A 10 kg mass therefore weighs about 98.0665 N. Mass stays the same everywhere, but weight changes with gravity: the same 10 kg would weigh only about 16 N on the Moon.
Where is Newton's second law used?
Everywhere a force changes motion: the thrust a rocket needs, the braking force on a car, the impact force in a crash, the push a sprinter applies off the blocks. Engineers use it to size engines, structures and safety systems for the accelerations they must withstand.
Sources and last check
Information, not professional advice.