ur answer is A or also known as
When you push a child on a swing, you are doing work on the child because you are pushing against the force of gravity
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In collision of the steel ball and the steel plate, the collision is an inelastic collision and there is loss in the kinetic energy.
<h3>What are collisions?</h3>
Collisions occur when two objects that are moving in the same directions or in different direction meet each other and collide.
There are two types of collisions:
- elastic collision - the kinetic energy is conserved
- inelastic collision - there is a loss in kinetic energy
In the collision of the steel ball and the steel plate, there is loss in the kinetic energy of the steel ball which is converted to sound energy.
In conclusion, the collision of the steel and steel plate is an inelastic collision.
Learn more about collisions at: brainly.com/question/7694106
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Answer:
The ratio of their orbital speeds are 5:4.
Explanation:
Given that,
Mass of A = 5 m
Mass of B = 7 m
Radius of A = 4 r
Radius of B = 7 r
The orbital speed of satellite A,
......(I)
The orbital speed of satellite B,
......(I)
We need to calculate the ratio of their orbital speeds
Using equation (I) and (II)

Put the value into the formula


Hence, The ratio of their orbital speeds are 5:4.
Length of the cord..........................................................
Question:
The water molecules now in your body were once part of a molecular cloud. Only about onemillionth of the mass of a molecular cloud is in the form of water molecules, and the mass density of such a cloud is roughly 2.0×10−21 g/cm^3.
Estimate the volume of a piece of molecular cloud that has the same amount of water as your body.
Answer:
The volume of cloud that has the same density as the amount of water in our body is 1.4×10²⁵ cm³
Explanation:
Here, we have mass density of cloud = 2.0×10⁻²¹ g/cm^3
Density = Mass/Volume
Volume = Mass/Density = If the mass is 40 kg and the body is made up of 70% by mass of water, we have
28 kg water = 28000 g
Therefore the Volume = 28 kg/ 2.0×10⁻²¹ g/cm^3 = 1.4×10¹⁹ m³ = 1.4×10²⁵ cm³.
Therefore, the volume of cloud that has the same density as the amount of water in our body = 1.4×10²⁵ cm³.