Answer:
Explanation:
Impulse of reaction force of floor = change in momentum
Velocity of impact = √ 2gh₁
= √ 2 x 9.8 x 1.5 = 5.4 m /s.
velocity of rebound = √2gh₂
= √ 2x 9.8 x 1
= 4.427 m / s.
Initial momentum = .050 x 5.4 = .27 kg m/s
Final momentum = .05 x 4.427 = .22 kg.m/s
change in momentum = .27 - .22 = .05 kg m/s
Impulse = .05 kg m /s
Impulse = force x time
force = impulse / time
.05 / .015 = 3.33 N.
kinetic energy = 1/2 m v²
Initial kinetic energy = 1/2 x .05 x 5.4²
= 0.729 J
Final Kinetic Energy =1/2 x .05 x 4.427²
= 0.489 J
Change in Kinetic energy =0 .24 J
Lost kinetic energy is due to conversion of energy into sound light etc.
Answer:
A force
Explanation:
A push or a pull is an example of a force and can cause an object to speed up, slow down, etc.. Newton's laws tell us that 1- an object will not change its motion unless a force acts on it 2- the force on an object is equal to its mass times its acceleration. 3- The third law states that for every action (force) in nature there is an equal and opposite reaction.. However, forces like gravity and friction can resist movement.
Answer:
Metal is more dense than water.
Explanation:
As we know, the molecules of the metal are tightly closed as compared to that of water and the density of a material is defined as the mass of the material per unit volume.
In a certain volume of metal, there are more numbers of molecules than that of water in the same amount of volume, therefore the density of metal is greater than that of water.
Also, according to Archimedes' principle, if there is an object in a fluid, then the buoyant force on that object is equal to the weight of the fluid that it displaces.
When the density of the object is larger than that of the fluid then it overcomes that buoyant force and sinks.
Thus, an object sinks in a fluid if its density is larger than that of the fluid and floats otherwise.
Since, the metal sink in water, it means Metal is more dense than water.
Mass & Height above the ground
