Answer:
Make a nice powerpoint and think about the question
Explanation:
Its easier than you think :)
When the object is at rest, there is a zero net force due the cancellation of the object's weight <em>w</em> with the normal force <em>n</em> of the table pushing up on the object, so that by Newton's second law,
∑ <em>F</em> = <em>n</em> - <em>w</em> = 0 → <em>n</em> = <em>w</em> = <em>mg</em> = 112.5 N ≈ 113 N
where <em>m</em> = 12.5 kg and <em>g</em> = 9.80 m/s².
The minimum force <em>F</em> needed to overcome <u>maximum</u> static friction <em>f</em> and get the object moving is
<em>F</em> > <em>f</em> = 0.50 <em>n</em> = 61.25 N ≈ 61.3 N
which means a push of <em>F</em> = 15 N is not enough the get object moving and so it stays at rest in equilibrium. While the push is being done, the net force on the object is still zero, but now the horizontal push and static friction cancel each other.
So:
(a) Your free body diagram should show the object with 4 forces acting on it as described above. You have to draw it to scale, so whatever length you use for the normal force and weight vectors, the length of the push and static friction vectors should be about 61.3/112.5 ≈ 0.545 ≈ 54.5% as long.
(b) Friction has a magnitude of 15 N because it balances the pushing force.
(c) The object is in equilibrium and not moving, so the acceleration is zero.
Answer:
The change in height of the mercury is approximately 2.981 cm
Explanation:
Recall that the formula for thermal expansion in volume is:
from which we solved for the change in volume 
due to a given change in temperature 
We can estimate the initial volume of the mercury in the spherical bulb of diameter 0.24 cm ( radius R = 0.12 cm) using the formula for the volume of a sphere:
Therefore, the change in volume with a change in temperature of 36°C becomes:
Now, we can use this difference in volume, to estimate the height of the cylinder of mercury with diameter 0.0045 cm (radius r= 0.00225 cm):
Answer:
the velocity of the point P located on the horizontal diameter of the wheel at t = 1.4 s is 
Explanation:
The free-body diagram below shows the interpretation of the question; from the diagram , the wheel that is rolling in a clockwise directio will have two velocities at point P;
- the peripheral velocity that is directed downward
along the y-axis
- the linear velocity
that is directed along the x-axis
Now;
Also,
where 
(angular velocity) = 
∴ the velocity of the point P located on the horizontal diameter of the wheel at t = 1.4 s is
Answer:
The correct answer is - option C. G.
Explanation:
In this reaction diagram, there is a representation of the reaction profile. The reaction profile shows the change that takes place during a reaction in the energy of reactants or substrate and products. In this profile, activation energy looks like a hump in the line, and the minimum energy required to initiate the reaction.
The overall energy of the reaction, including or excluding activation energy depends on the nature of the reaction if it is exothermic or endothermic. and products are represented by the G which shows the difference between the energy of the reactants and products.
