Interactive physics simulator
Acceleration
Acceleration tells how quickly velocity changes with time. An object accelerates when it speeds up, slows down, or changes direction.
Acceleration Simulator
Arrows show direction; a longer velocity arrow means faster motion.
Live Result
- Initial velocity u
- 0 m/s
- Final velocity v
- 20 m/s
- Current velocity
- 0 m/s
- Acceleration
- 4 m/s²
- Time t
- 5 s
- Elapsed time
- 0 s
- Distance / height
- 0 m
- Remaining height
- not used
- Formula
- v = u + at
What is Acceleration?
Acceleration is how fast velocity changes each second. A car speeding up has acceleration, a bike braking has negative acceleration, and an object turning has acceleration because its direction changes.
Key Definition
Acceleration is the rate of change of velocity with time.
- Acceleration tells how quickly velocity changes.
- An object accelerates when it speeds up.
- An object also accelerates when it slows down.
- An object can accelerate when it changes direction.
- Acceleration is a vector quantity.
- SI unit is meter per second squared, written as m/s².
Acceleration Formula
Acceleration = Change in Velocity / Time a = (v - u) / t v = u + at s = ut + 1/2at² Variables and units
- a = acceleration
- u = initial velocity
- v = final velocity
- t = time in seconds
- velocity in m/s, time in seconds, acceleration in m/s²
Types of Acceleration
Positive Acceleration
Velocity increases. Example: a car speeding up.
Negative Acceleration
Velocity decreases in a simple straight-line case. It is often called deceleration.
Direction Change
Velocity changes because direction changes. Example: turning on a circular path.
Real-life Example of Acceleration
A car starts from rest and reaches 20 m/s in 5 seconds.
Initial velocity = 0 m/s Final velocity = 20 m/s Acceleration = (20 - 0) / 5 = 4 m/s² - A ball falling down speeds up due to gravity.
- A bicycle slows down when brakes are applied.
Solved Examples
View Solution: A car increases its velocity from 0 m/s to 20 m/s in 5 s. Find acceleration.
a = (v - u) / t
a = (20 - 0) / 5
a = 4 m/s^2
Final answer: 4 m/s^2
View Solution: A bike slows from 15 m/s to 5 m/s in 5 s. Find acceleration.
a = (5 - 15) / 5
a = -10 / 5
a = -2 m/s^2. The negative sign means the bike is slowing down in the chosen positive direction.
Final answer: -2 m/s^2
View Solution: A ball is dropped from rest. What is its velocity after 3 s on Earth?
v = u + gt
v = 0 + 9.8 x 3
v = 29.4 m/s downward
Final answer: 29.4 m/s downward
Common Mistakes
- Confusing acceleration with speed.
- Thinking acceleration only means speeding up.
- Forgetting that slowing down is also acceleration.
- Forgetting the unit m/s².
- Using speed instead of change in velocity.
- Forgetting to subtract initial velocity from final velocity.
- Forgetting time must be in seconds for SI calculations.
- Ignoring direction or sign.
Quick Summary
- Acceleration means change in velocity per time.
- Formula: a = (v - u) / t.
- SI unit is m/s².
- Acceleration is a vector quantity.
- Positive acceleration means velocity increases in the positive direction.
- Negative acceleration often means slowing down.
- Gravity causes falling objects to accelerate downward.
- On Earth, g ≈ 9.8 m/s².
Practice Questions
1. Show Answer: A car speeds up from 0 m/s to 30 m/s in 10 s. Find acceleration.
Step: Use the acceleration formula and keep time in seconds.
a = (30 - 0) / 10 = 3 m/s^2.
2. Show Answer: A bike slows from 20 m/s to 8 m/s in 4 s. Find acceleration.
Step: Use the acceleration formula and keep time in seconds.
a = (8 - 20) / 4 = -3 m/s^2.
3. Show Answer: A ball is dropped from rest. What is its velocity after 2 s on Earth?
Step: Use the acceleration formula and keep time in seconds.
v = 0 + 9.8 x 2 = 19.6 m/s downward.
4. Show Answer: What is the SI unit of acceleration?
Step: Use the acceleration formula and keep time in seconds.
The SI unit is meter per second squared, written as m/s^2.
5. Show Answer: Is acceleration scalar or vector?
Step: Use the acceleration formula and keep time in seconds.
Acceleration is a vector quantity because direction matters.
6. Show Answer: Does an object accelerate when it changes direction?
Step: Use the acceleration formula and keep time in seconds.
Yes. A change in direction is a change in velocity, so it is acceleration.
Frequently Asked Questions
What is acceleration in physics?
Acceleration is the rate at which velocity changes with time.
What is the formula for acceleration?
The formula for acceleration is a = (v - u) / t, where v is final velocity, u is initial velocity, and t is time.
What is the SI unit of acceleration?
The SI unit of acceleration is meter per second squared, written as m/s².
Is acceleration scalar or vector?
Acceleration is a vector quantity because it has magnitude and direction.
Does acceleration only mean speeding up?
No. Acceleration means any change in velocity. This can mean speeding up, slowing down, or changing direction.
What is negative acceleration?
Negative acceleration means acceleration in the negative direction. In simple cases, it often means the object is slowing down.
What is acceleration due to gravity?
Acceleration due to gravity is the acceleration an object experiences when falling because of gravity. Near Earth’s surface, it is about 9.8 m/s² downward.
Why is time important in acceleration?
Time is important because acceleration measures how much velocity changes every second.
How does the acceleration simulator work?
The simulator uses initial velocity, acceleration, and time to calculate current velocity and distance as the object moves.
Can acceleration be zero?
Yes. Acceleration is zero when velocity does not change.