Answer:
Mass of the box = 0.9433 kg
Explanation:
Mass of racket-ball
= 0.00427 kg
Velocity of racket-ball before collision
= 22.3 m/s
Velocity of racket-ball after collision with box
= -11.5 m/s
[Since ball is bouncing back, so velocity is taken negative.]
Velocity of the box before collision
= 0 m/s
<em>[Since the box is stationary, so velocity is taken zero]</em>
Velocity of box moving forward after collision
= 1.53 m/s
To find the mas of the box
.
By law of conservation of momentum we have:
Momentum before collision = Momentum after collision
This can be written as:


We can plugin the given value to find 


Adding both sides by 0.4911


Dividing both sides by 1.53.


∴
kg
Mass of the box = 0.9433 kg (Answer)
1. Answer: Option C
Displacement is a vector quantity. It has both magnitude as well as direction. Hence, it can be positive, zero or negative. In the given question, downward direction is taken as negative. This we have come to know from the downward acceleration
. The negative sign indicates that downward direction is considered negative.
Now, since the object is dropped from the top. The displacement should be negative, because the negative represent a downward direction.
2. Answer: velocity
The truck is travelling at 30 mph to the west. From the unit mph (miles per hour), we know its a magnitude of velocity. West indicates the direction. Hence, the given quantity is a vector -velocity.
It is not speed because speed only indicates the magnitude and not the direction. speed is a scalar quantity.
Answer
The answer and procedures of the exercise are attached in the following archives.
Step-by-step explanation:
You will find the procedures, formulas or necessary explanations in the archive attached below. If you have any question ask and I will aclare your doubts kindly.
A: Some physical properties change, but the substance keeps its identity.
Answer:
a. They will be tie
b. Win the wood cylinder
Explanation:
a.
The both cylinders will reach the bottom at the same time notice the relation in the equation in indepent of the length and both have the same radius and the same rotational inertia.


So both will be tie
b.

The acceleration of the wood cylinder is larger than the acceleration of the brass cylinder so the cylinder of wood will reach the bottom first

So the wood win the race