An object with a mass of 1.5 kg changes its velocity from +15 m/s to +22 m/s during a time interval of 3.5 seconds. What impulse was delivered to the object?
Momentum = (mass) x (speed).
Original momentum = (1.5 kg) x (15 m/s) = 22.5 kg-m/s
New momentum = (1.5 kg) x (22 m/s) = 33 kg-m/s .
The change in momentum is (33 - 22.5) = +10.5 kg-m/s.
The change in the object's momentum is identical to
the impulse delivered to it.
Answer : Impulse, I = 10.5 kg-m/s
Explanation :
It is given that,
Mass of an object, m = 1.5 kg
Initial velocity of the object, u = 15 m/s
Final velocity of the object, v = 22 m/s
Time duration, t = 3.5 s
We know that the impulse is equal to the change in momentum of an object.
i.e.
\(\because F=ma\)
\(a=\dfrac{\Delta v}{\Delta t}\)
\(I=F.\Delta t=m.\Delta v\)
\(I=1.5\ kg(22\ m/s-15\ m/s)\)
\(I=10.5\ kg\ m/s\)
Hence, the impulse delivered to the object is 10.5 kg-m/s.