<u>Answers
</u>
1) P = mv
2) Kg.m/s
3) The product of the force applied to the object and the time interval.
4) Momentum
5) A large constant force acting over a long time interval causes a large change in momentum.
6) Was conserved
7) Is conserved
8) Unchanged.
9) Must also be the same
10) 10 m/s, north
11) Perfectly elastic.
<u>Explanation
</u>
1)
Momentum is the product of velocity and the mass. That is;
Momentum = velocity × mass
. Where p -- momentum, <em>P= mv</em>
2)
Since; momentum = velocity × mass, we can derive the S.I units.
Velocity – m/s
Mass – Kg.
So the SI units will be (Kg×m/s) = <em>Kg.m/s
</em>
3)
From the newton’s second law of motion,
F=Ma = (mv – mu)/t
Ft = mv – mu. <em>Change in momentum is also equal to the product of force and time. </em>
4)
Impulse is the force acting on an object for a short time. It is calculated as;
Impulse = ft = change in momentum.
So the answer is<em> momentum </em>
6)
When to bodies collide, the collision may result into an elastic or inelastic collision. In both cases the momentum will be<em> conserved. </em>
7)
When the shopping cart collides with the wall, the momentum before colliding and after colliding will be the same. The momentum is always <em>conserved.</em>
8)
There are two types of collision. Elastic and in-elastic collision. In an elastic collision both momentum and K.E are conserved while in an in-elastic collision only momentum is conserved. So the kinetic energy<em> is unchanged. </em>
9)
At all cases of collision the momentum is always conserved. So is kinetic energy was conserved then, momentum must also have been <em>conserved. </em>
<em>10)
</em>
Momentum before collision = momentum after collision
Taking the velocity towards north to be positive,
(90 × V) + (120×-4) = (90+120)× 2
90V – 480 = 210 × 2
90V = 420+480
V = 900/90
= 10 m/s
Since the answer is positive, the answer is <em>10 m/s, north.
</em>
11)
There are two types of collision. Elastic and in-elastic collision. In an elastic collision both momentum and K.E are conserved while in an in-elastic collision only momentum is conserved. So the answer is <em>perfectly elastic. </em>