Answer:
Because the mechanical advantage of the machine is affected by friction and weight but velocity ratio is not. So, mechanical advantage is less than velocity rate. Thus, the machine's efficiency is less than 100% and can't be a perfect machine
Answer:
i think it is c if not im sorry if im wrong
Explanation:
TRUE.
Taste and smell senses are separate senses with their own receptor organs yet they are intimately entwined. Tastants, chemicals in foods are detected by taste buds which consist of special sensory cells.. When stimulated, these cells send signals to specific areas of the brain which then makes us conscious of the perception of taste. Also specialized cells in the nose pick up odorants, airborne odor molecules. Odorants stimulate receptor proteins found on hairlike cilia at the tips of the sensory cells, a process that initiates a neural response.
In general the higher we go the cooler it becomes . temperature fall continues within the lowermost layer of our atmosphere, known as the troposphere. Above the troposphere, the stratosphere exists and in this region the temperature increases with an increase in altitude. The mesosphere is the part of the atmosphere that lies above the stratosphere. In this region, the temperature falls with an increase in altitude. And finally as we continue rising up, we reach the thermosphere, where the temperature increases with increased altitude.
The tennis ball lands at a point 40.4 m from the base of the building.
The tennis ball is projected with a horizontal velocity <em>u</em> from a window, which is at a height <em>y</em> from the ground. The ball lands at a distance <em>x</em> from the base of the building. Let the ball take a time <em>t</em> to reach the ground. In the time <em>t</em> ,the ball falls a vertical distance <em>y</em> and also travel a horizontal distance <em>x</em>.
The initial vertical velocity of the ball is zero, since the ball is projected in the horizontal direction. The ball falls down under the action of gravitational force.
Thus, use the equation of motion,

rewrite the expression for <em>t</em> and calculate the value of <em>t</em> using 9.81 m/s²for <em>g</em> and 500 m for <em>y</em>.

The horizontal distance <em>x</em> is traveled using the constant velocity <em>u </em>since no force acts on the ball in the horizontal direction.
Therefore,

Substitute 4 m/s for <em>u</em> and 10.096 s for <em>t</em>

Thus, the ball lands at a point 40.4 m from the base of the building.