# B Question about getting Force

1. Jun 21, 2017

### John Clement Husain

can we get Force with velocity and mass only?

2. Jun 21, 2017

### Staff: Mentor

Force of what, where, in which setup? Mass and velocity of what?

Is this a homework problem?

3. Jun 22, 2017

### John Clement Husain

No it isn't. Like the force of a punch or a rocket

4. Jun 22, 2017

### Staff: Mentor

Not without context.

A rocket at a given mass and velocity can either use its thrusters or not use them. The resulting force will be very different.

5. Jun 22, 2017

### Staff: Mentor

I think you mean impact force? An object in motion does not just "have force".

And the answer is still no: force for an impact(collision) is determined by the rate of deceleration, which depends also on the structure of the objects colliding. It doesn't have a single value and the variation throughout the impact can be very complex.

6. Jun 23, 2017

### olgerm

Do you mean formula $F=\frac{dp}{dt}=m\cdot\frac{dv}{dt}$?

7. Jun 25, 2017

### David Lewis

It takes force to change the velocity of a mass.