Question

1.

Answer 1

Answers

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.  

Explanation

1)

Momentum is the product of velocity and the mass. That is;

Momentum = velocity × mass . Where p -- momentum, P= mv

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) = Kg.m/s

3)

From the newton’s second law of motion,  

F=Ma = (mv – mu)/t

Ft = mv – mu.  Change in momentum is also equal to the product of force and time.  

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 momentum

6)

When to bodies collide, the collision may result into an elastic or inelastic collision. In both cases the momentum will be conserved.  

7)

When the shopping cart collides with the wall, the momentum before colliding and after colliding will be the same. The momentum is always conserved.  

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 is unchanged.  

9)

At all cases of collision the momentum is always conserved. So is kinetic energy was conserved then, momentum must also have been conserved.  

10)

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 10 m/s, north.

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 perfectly elastic.  

Answer 2

11.Perfectly elastic,as in only this collision K.E is conserved,however momentum is conserved in both elastic and inelastic collisions. 9)must also be conserved.because there is eleastic collision. 8)unchanged. 7)dcreases as velocity changes from 0.5 to 0 m/s. 4)momentum