In a real system of levers, wheel or pulleys, the AMA (actual mechanical advantage) is less than the IMA (ideal mechanical advantage) because of the presence of friction.
In fact, the IMA and the AMA of a machine are defined as the ratio between the output force (the load) and the input force (the effort):

however, the difference is that the IMA does not take into account the presence of frictions, while the AMA does. As a result, the output force in the AMA is less than the output force in the IMA (because some energy is dissipated due to friction), and the AMA is less than the IMA.
Answer:
The first answer is 7,24g Mg
The second answer is 3,36L O2
Explanation:
Atomic masses: Mg= 24,3 ; O=16
Solution: MMgO = 40,3 g/mol
2 Mg + O2 => 2 MgO
1) 12 g MgO x (2x24,3 g Mg / 2x 40,3 MgO) = 7,24 g Mg
2)
At first calculate moles from Oxygen:
12 g MgO x ( 1 mol from Oxygen/ 2 x 40,3 g MgO ) = 0,15 moles from Oxygen
then ....
0,15 moles from Oxygen x (22,4 lts / 1 mol from Oxygen ) = 3,36 lts
22.4 liters is the constant that we use in this equation, it is a value that is repeated since we are in the presence of a gas with ideal behavior, so it is considered that the normal molar volume of ideal gaseous substances is always 22.4 liters, estimated with a temperature of 0º C and a pressure of 1 atmosphere. (constant temperature and pressure)
The characteristics of the projectile launch allows to find the results for the questions about the movement of the ball are:
-
In the attached we see the vertical speed decreases with height and the curve is of the parabolic type.
- In the movement is several dimensions, each one is independent of the others, the movement in the x axis does not affect the movement in the y axis.
Kinematics studies the motion of bodies looking for relationships between position, velocity and acceleration. In the case of vertical and projectiles launch the acceleration on the vertical axis is the acceleration of gravity directed downward.
In the attachment we can see the position of the ball for two distances in the case of projectile launching.
We can see that the speed of the ball decreases with height according to the relation
y = go t - ½ g t²
Where y is the height, g is the initial vertical velocity, g is the acceleration of gravity and t is time.
In all movements in various dimensions we assume that each movement in an .
axis is independent
In the case of projectile launching, on the vertical axis there is an acceleration of gravity and on the horizontal axis there is no acceleration, the only parameter that this gives the two movements is the time, which is a scalar.
In conclusion, using the characteristics of the projectile launch, we can find the results for the questions about the movement of the ball are:
- In the movement is several dimensions, each one is independent of the others, the movement in the x axis does not affect the movement in the y axis.
- In the attached we see the vertical speed decreases with height and the curve is of the parabolic type.
Learn more about projectile launch here: brainly.com/question/24888457
Answer:
d) Decrease, increase, remain constant
Explanation:
If one tire has a slow leak, the air pressure within the tire will_DECREASE____with time due to outflow of air , the surface area between the tire and the road will__INCREASE__in time,due to flattening of tire.
The net force the tire exerts on the road will_REMAIN CONSTANT____in time. It is so because force does not depend upon area. It is pressure which depends upon area. As there is no change in the weight of the car , force on the road will remain constant.