Answer: Tides are periodic rises and falls of large bodies of water. Tides are caused by gravitational interaction between the earth and the moon. The gravitational attraction of the moon causes the oceans to bulge out in the direction of the moon.
Answer:
Frictional force always acts parallel to two planes in contact with each other and in a direction opposite to that of relative motion of the two bodies. 2. Frictional forces are caused due to intermolecular interactions between the bodies. Frictional force is more for rough surface and less for smooth surfaces.
Answer:
a.73.3%
b.26.6%
Explanation:
a. The efficiency is the energy output, divided by the energy input, and expressed as a percentage.
#Given the energy input as 1500J and the subsequent output as 1100J, the TV's efficiency is calculated as:
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Hence, the TV has an efficiency of 33.3%
b. From a above, we know that the TV has an output of 1100J and input of 1500J.
-We therefore calculate it's wastage as the difference between output and input:
<em>Wastage=Energy Input-Energy Output=1500J-1400J=400J</em>
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Hence, the TV has wasted of 26.6%
Answer:
Intermolecular forces
Explanation:
The force of attractions that act between molecules are called intermolecular forces.
Their nature is electromagnetic, this means that they are just an expression of the electromagnetic force.
One example of intermolecular force is the ionic bond: this type of bond occurs when there are two ions, one positively charged and the other one negatively charged, and they are attracted by each other due to the electrostatic force, which therefore creates a bond between them.
Other types of intermolecular forces include:
Hydrogen bond
Ion-dipole forces
Van der Waals forces
The strength of these intermolecular forces determine the state of the substance. In fact, in solids, these forces are very strong, so that the molecules are strongly bond to each other and they cannot move freely, but only vibrate about their fixed position. On the other hand, in gases, these forces are very weak, therefore the molecules are able to move freely away from each other.
