Question #b1ade

2 Answers

#F=m * a#

Explanation:

#"Force" = "mass" xx "acceleration"#

Rate of change of momentum is directly proportional to force.
Change in momentum can be

#m * v_2 - m * v_1 = m * Deltav#, where #v_2# and #v_1# are different velocities.

Rate of change of momentum is

#d/(dt)(mv) = m * (dv)/(dt)#

But #(dv)/(dt)# is acceleration, so

#F = m * a#

Sep 4, 2015

#vec(F)=mvec(a)#

Explanation:

Newton's he second law of motion describes how the motion of an object behaves under the influence of an external force. Here #vec(F)# is the total force on an object, this is a vector, since it has both a direction and a magnitude, #m# the mass of the object and #vec(a)# the acceleration of the object, which is also a vector.

The law can also be written in a couple of different ways. since the acceleration is the change in velocity, and velocity the change in place, we can write #vec(a)=d/dtvec(v)=d/dtd/dtvec(x)=d^2/dt^2vec(x)#.
This means #vec(F)=md/dtvec(v)=d^2/dt^2vec(x)#.

Since the total mass of an object is usually constant, we can pull #m# through the derivation, meaning #vec(F)=(d(mvec(v)))/dt#. Since we have the momentum of an object #vec(p)=mvec(v)#, we can state
#vec(F)=(dvec(p))/dt#.
This can be used to show that in an isolated system the total momentum of all objects is conserved, which is an important result in classical physics.