The velocity of an object with a mass of #3 kg# is given by #v(t)=  t^2 +4 t #. What is the impulse applied to the object at #t= 5 #?
1 Answer
Answer:
The impulse of an object is associated to a change on its linear momentum,
Let us calculate it for
Explanation:
Let us suppose that the object starts its motion at
Linear momentum is given by:

At
#t=0# , linear momentum is:
#p(0) = m cdot v(0) = 3 cdot (0^2 + 4 cdot 0) = 0# 
At
#t=5# , linear momentum is:
#p(5) = m cdot v(5) = 3 cdot (5^2 + 4 cdot 5) = 15 " kg" cdot "m/s"#
So impulse finally is given by:
The negative sign just means that the object is moving backwards.
P.S.: the vectorial expression is