Answer:
The object will have an upward acceleration
Explanation:
Let's consider the forces applied on the box. We have only two forces:
- The applied force of push, 
, downward
- The force of gravity, 
, (also known as weight of the object), downward
Therefore, the net force on the box is:
Here, we know that force applied is equal or greater than the weight, so
And therefore the net force is greater than zero:
(1)
According to Newton's second law of motion, the net force on the box is equal to the product between its mass and its acceleration:
where
m is the mass of the box
a is its acceleration
Given (1), this means that
Therefore, the box will have an upward acceleration.
In this case force example we have:
So the mass of the box is
So the net force is
And the acceleration is
Answer:
5730 years
Explanation:
The half life of carbon-14 is 5730 years. If 50% of the carbon-14 remains, then exactly 1 half life has passed.
The half-life equation is:
A = A₀ (½)^(t / T)
where A is the remaining amount,
A₀ is the initial amount,
t is time,
and T is the half life.
In this case, A = ½ A₀ and T = 5730.
½ A₀ = A₀ (½)^(t / 5730)
½ = (½)^(t / 5730)
1 = t / 5730
t = 5730
<u>Answer
</u>
A. 1 and 2
<u>Explanation
</u>
At point 1 we have the highest potential energy and the kinetic energy is zero.
At 2 the potential energy is minimum and the kinetic energy is maximum.
The law of conservation of energy says that energy cannot be created nor destroyed. So, the change in P.E = Change in K.E.
P.E = height × gravity × mass. The height referred here is the perpendicular height. Gravity and mass are constant in this case.
From the diagram it can be seen clearly that the vertical height from 2 to 1 is much greater than from 4 to 3.
This shows that the change in P.E is greater between 1 and 2 and so is kinetic energy.
5.972 × 10^24 kg
it is the weight of earth
hope it is helpful to you
