Answer
Correct answers are 1.an increase or decrease in pressure 2.an increase or decrease in energy
Explanation
All existing matter can undergo phase change it means they may transform from one state to another. phase change of a matter may occur due to change in energy and change in pressures.
for example there is an ice cube which is a solid and if we want to change it phase into liquid water for that purpose we have to supply some energy to ice cube it means we have to give some heat to ice cube. After supplying heat energy to the ice it will turn into water it means there is phase change from solid to liquid due to supplying the heat. Similarly we can change the liquid water into solid ice cube by taking heat energy(reducing temperature) from the liquid water .
In some cases the matter doesn't want to undergo phase transformation. For example, oxygen will solidify at -361.8 degrees Fahrenheit at standard pressure.But , it can change to solid state at warmer temperatures when the pressure is increased.
Answer:
70.6 mph
Explanation:
Car A mass= 1515 lb
Car B mass=1125 lb
Speed of car B is 46 miles/h
Distance before locking, d=19.5 ft
Coefficient of kinetic friction is 0.75
Initial momentum of car B=mv where m is mass and v is velocity in ft/s
46 mph*1.46667=67.4666668 ft/s
Initial momentum of car A is given by
where 
is velocity of A
Taking East as positive and west as negative then the sum of initial momentum is
The common velocity is represented as 
hence after collision, the final momentum is
From the law of conservation of linear momentum, sum of initial and final momentum equals each other hence
The acceleration of two cars 
From kinematic equation
hence
Substituting the value of in equation
Answer:
Law 1. A body continues in its state of rest, or in uniform motion in a straight line, unless acted upon by a force.
Law 2. A body acted upon by a force moves in such a manner that the time rate of change of momentum equals the force.
Law 3. If two bodies exert forces on each other, these forces are equal in magnitude and opposite in direction.
Answer:
The gravitational potential energy of the ball is 13.23 J.
Explanation:
Given;
mass of the ball, m = 0.5 kg
height of the shelf, h = 2.7 m
The gravitational potential energy is given by;
P.E = mgh
where;
m is mass of the ball
g is acceleration due to gravity = 9.8 m/s²
h is height of the ball
Substitute the givens and solve for gravitational potential energy;
PE = (0.5 x 9.8 x 2.7)
P.E = 13.23 J
Therefore, the gravitational potential energy of the ball is 13.23 J.
