Answer:
-24 m/s
Explanation:
mass of the bowling ball = 3 kg
time (t) = 0.3 seconds
Force = 24 N
initial velocity u = ???
We know that;
Force = mass × acceleration (a)
So;
24 = 3 × a
a = 24/3
a = 8 m/s²
Also;
From equation of motion; acceleration is given by the relation;

if v = 0
then ;

24 = 0- u
u = -24 m/s
Thus; the initial velocity of the bowling ball when it first touched the mattress = -24 m/s
The given question is incomplete. The complete question is as follows.
A box of oranges which weighs 83 N is being pushed across a horizontal floor. As it moves, it is slowing at a constant rate of 0.90 m/s each second. The push force has a horizontal component of 20 N and a vertical component of 25 N downward. Calculate the coefficient of kinetic friction between the box and the floor.
Explanation:
The given data is as follows.
= 20 N,
= 25 N, a = -0.9
W = 83 N
m = 
= 8.46
Now, we will balance the forces along the y-component as follows.
N = W +
= 83 + 25 = 108 N
Now, balancing the forces along the x component as follows.
= ma
= 7.614 N
Also, we know that relation between force and coefficient of friction is as follows.

= 
= 0.0705
Thus, we can conclude that the coefficient of kinetic friction between the box and the floor is 0.0705.
Answer:closed systems
Explanation:
A closed system is one in which matter does not enter or leave the system but there is exchange of energy between the system and its environment. In a closed system, the principle of energy conservation applies. The principle of energy conservation states that energy can neither be created nor destroyed but is converted from one form to another. An example of a closed system is a reaction vessel whose lid is closed.
Answer:
The oven has many different heat sources from the bottom, sides, top, etc...
The microwave only has the sides.