The frictional force produces the negative acceleration (often called deceleration) that reduces the velocity of the vehicle from its initial unknown speed to zero. Find the value of the frictional force.
F= m a
To find the value of the frictional force that produces the deceleration, we can use Newton's second law of motion. According to this law, the net force acting on an object is equal to the mass of the object multiplied by its acceleration.
In this case, since we know the deceleration and want to find the frictional force, we can rearrange the equation to solve for the force.
Step 1: Write down the given information:
- Deceleration (a) = negative acceleration
- Mass of the vehicle (m) = unknown
- Initial velocity of the vehicle (u) = unknown
- Final velocity of the vehicle (v) = 0 (because the vehicle comes to a stop)
Step 2: Identify the equation that relates the variables:
The equation that relates force (F), mass (m), and acceleration (a) is:
F = m * a
Step 3: Rearrange the equation to solve for the frictional force:
F = m * a
Step 4: Substitute the given values into the equation and solve for the frictional force:
F = m * (-a)
Since the vehicle comes to a stop, its final velocity (v) is 0. We can calculate the deceleration (a) using the equation:
a = (v - u) / t
Since we know the final velocity (v) is 0, the equation simplifies to:
a = -u / t
Now, substitute this value of a into the equation for F:
F = m * (-a)
F = m * (-(-u / t))
F = m * (u / t)
Therefore, the value of the frictional force (F) is given by the equation:
F = (m * u) / t
To find the value of the frictional force, we need to know the mass of the vehicle (m), its initial velocity (u), and the time taken for the vehicle to come to a stop (t).