Lighting is the static electricity stored in the clouds that is disposed to the earth.
Answer: C Plane
Explanation: According to Newton's law, gravitational force is proportional to the product of masses and inversely proportional to the square of distance between them.
Gravitational force depends on mass. The bigger the mass, the more the magnitude of the gravitational force. Since plane is assume to have the highest mass in the options, we can therefore conclude that plane will experience the highest gravitational force.
Answer:
2 seconds
Explanation:
The frequency of a wave is related to its wavelength and speed by the equation
where
f is the frequency
v is the speed of the wave
is the wavelength
For the wave in this problem,
v = 2 m/s
So the frequency is
The period of a wave is equal to the reciprocal of the frequency, so for this wave:
This means that the wave takes 4 seconds to complete one full cycle.
Therefore, the time taken for the wave to go from a point with displacement +A to a point with displacement -A is half the period, therefore for this wave:
as well.
1. Correct
Explanation
An inclined plane is a flat surface which lie at an angle, Its one end is higher than the other this inclined plane is used as an aid for raising or lowering a load. Staircase also work in similar manner
2. Correct
Explanation
yes all simple machine have a fulcrum
3. Incorrect
Explanation
when we swim that time our arms and legs 'push' the water due to which water displaced in backward direction so her we applied a positive work on the water. According to Newton's Third Law,same magnitude of work is done by water in opposite direction to push us back on our arms and legs. therefore water also does positive work on us.
4. incorrect
Explanation
The force exerted by a machine on an object is input force
5. Incorrect
Explanation
when the input force is greater than the output force that time machine have mechanical advantage of less than 1.
