# Hi, I am confused about physics, more specifically force.

I know that the formula for force is:
f=ma

So what if an object traveling at constant speed (acc equals zero) collides with a wall? How would you calculate the force, since there is no acceleration?

There IS force upon the object, as well as acceleration, when collision occurs. Its velocity DOES change during the impact, since it must stop and turn around, stick or bounce off.

In order to calculate the force during impact, you need to know how long the objects are in contact. That depends upon the elastic properties of the surfaces where contact occurs, and whether permanent deformation occurs. This can be difficult to compute accurately. Often an experimental measurement is used

## You are correct that even if an object is traveling at a constant speed, it can still experience a force and acceleration during a collision. During a collision, the object's velocity changes as it either stops, turns around, sticks, or bounces off the wall.

To calculate the force during the impact, you would need to know how long the objects are in contact. This duration of contact depends on the elastic properties of the surfaces involved and whether any permanent deformation occurs. Calculating this accurately can be challenging, so often experimental measurements are used to determine the force.

One method to estimate the force during a collision is by using the concept of impulse. Impulse is defined as the product of the force applied to an object and the time over which it acts. So during a collision, the force can be calculated by measuring the change in momentum and dividing it by the duration of the collision.

The formula for impulse is:

Impulse = Change in momentum = m * ∆v

where m is the mass of the object and ∆v is the change in velocity during the collision.

Using the equation f = ma, where f is the force, m is the mass, and a is the acceleration, we can rearrange the impulse formula to solve for force:

f = ma = m * ∆v / t

where t is the duration of the collision.

In practice, to accurately determine the force during a collision, experimental methods like force sensors or measuring the duration of the collision are commonly used.