The correct answer to the question is : D) Be moving at a constant velocity.
EXPLANATION:
As per Newton's first laws of motion, every body continues to be at state of rest or of uniform motion in a straight line unless and until it is compelled by some external unbalanced forces acting on it.
Hence, it is the unbalanced force which changes the state of rest or motion of a body. Balanced force is responsible for keeping the body to be either in static equilibrium or in dynamic equilibrium.
As per the options given in the question, the last one is true for an object under balanced forces.
I think the first question is talking about the ionic compound Sodium sulfide and it’s formula is Na2S.
And for the second question, i’m pretty sure it’d be a positive charge
Answer:
D. Friction and air resistance created heat on his trip up the hill.
Explanation:
Energy transformation from one form to another is not 100% efficient. This is the postulate of the first law of thermodynamics.
Most of the energy transformation is not purely 100%.
When energy is transformed, some are usually wasted.
- In this case, in moving from bottom up, Superman produced some heat and encountered air resistance.
- To reach the top, he must have overcome the resistance and produce enough heat to power him through.
- This reduces the amount of potential energy that should have been the same as the kinetic energy down below.
A typical barometer measures the pressure of the location at where you're at. Once it displays the pressure, you can determine the height using the hydrostatic pressure. The equation is written below:
P = ρgh,
where
ρ is the density of air
g is the acceleration due to gravity
h is the height
Therefore, if the pressure increases, then the height also increases.
Answer:
4.53 second, 195 ft/s
Explanation:
u = 50 ft/s
h = 555 ft
g = 32 ft/s^2
Let the time taken by the ball to reach the ground is t and the velocity of the ball as it hits the ground is v.
Use third equation of motion
v = 195 ft /s
Thus, the ball strikes the ground with velocity 195 ft/s.
Use first equation of motion
v = u + at
195 = 50 + 32 t
32 t = 145
t = 4.53 second
Thus, the ball reach the ground in 4.53 second.
