The answer is a because it has a high melting tolerance
Answer: positive
Explanation: because opposites attract and north=positive and south=negative the answer should be positive.
Answer:
The box is moved at constant speed, then the change in kinetic energy is zero.
Explanation:
Let suppose that box moves at constant speed, meaning that its kinetic energy (
), measured in joules, is expressed by the following equation:
(1)
Where:
- Mass, measured in kilograms.
- Speed, measured in meters per second.
If the box moves at constant speed, then we notice that 
, therefore, 
. In a nutshell, if the box is moved at constant speed, then the change in kinetic energy is zero.
As the time of motion increases, the velocity of the object increases downwards.
The given parameters;
- <em>acceleration due to gravity, g = -9.81 m/s²</em>
- <em>velocity of the object, v₀ = 9.8 m/s</em>
The final velocity of the object at different time is calculated as follows;
<em>when the time = 1 second;</em>
v = v₀ - gt
v = 9.8 - 9.8(1)
v = 0
<em>when the time = 2 second;</em>
v = v₀ - gt
v = 9.8 - 9.8(2)
v = -9.8 m/s
<em>when the time = 3 second;</em>
v = v₀ - gt
v = 9.8 - 9.8(3)
v = -19.6 m/s
Thus, we can conclude that as the time of motion increases, the velocity of the object increases downwards.
Learn more here:brainly.com/question/16782759
Physical changes are temporary, such as an ice cube melting and chemical changes are more permanent, such as acid rain weathering off the side of a rock.
