Answer:
I = 15 kg.m/s
Explanation:
given,
mass of ball = 0.3 Kg
speed of the ball = 30 m/s
rebound speed = 20 m/s
impulse = ?
impulse is equal to change in momentum
I = m (Δ v)
I = m (v₂ - v₁)
I = 0.3 x (20 - (-30))
I = 0.3 x (50)
I = 15 kg.m/s
Impulse due to collision with the side walk is equal to I = 15 kg.m/s
The initial momentum of the ball is 15 Kgms-1.
<h3>What is momentum?</h3>
In Physics, the term momentum is the product of mass and velocity. Momentum is a vector quantity. This implies that momentum possess both magnitude and direction.
Hence, we often write; p = mv
Where:
p = momentum
m = mass
v = velocity
The initial momentum therefore is;
p = 1.25 kg × 12 m/s = 15 Kgms-1
Learn more about momentum: brainly.com/question/904448
The work that is done when twice the load is lifted twice the distance is
four times as much
The net work performed by forces acting on an object equals the change in kinetic energy, according to the work-energy theorem.
when an item slows down, the net work applied to it decreases, its change in kinetic energy is negative, and its ultimate kinetic energy is less than its starting kinetic energy. When an item accelerates, positive net work is done on it. All the forces acting on an item must be taken into consideration when determining the net work. You will obtain an incorrect result if you exclude any forces that affect an item or if you add any forces that do not affect it.
Hence The work that is done when twice the load is lifted twice the distance is four times as much
Learn more about Work here
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Answer:
(a) K₁ = 2.205 J.
(b) K₂ = 5.733 J.
(c) K₂/K₁ = 2.6.
Explanation:
Kinetic Energy: This can be defined as the energy of a body in motion. The Unit of kinetic energy is J.
Mathematically kinetic energy can be represented as,
K = 1/2mv²
(a)
K₁ = 1/2m₁v₁²............................ Equation 1
Where K₁ = kinetic energy of the smaller bullet, m₁ = mass of the smaller bullet, v₁ = velocity of the smaller bullet.
<em>Given: m₁ = 2.5 g = 2.5/1000 = 0.0025 kg, v = 42 m/s.</em>
<em>Substituting these values into equation 1</em>
K₁ = 1/2(0.0025)(42)²
K₁ = 4.41/2
K₁ = 2.205 J.
(b)
K₂ = 1/2m₂v₂²............................. Equation 2
Where K₂ = kinetic energy of the heavier bullet, m₂ = mass of the heavier bullet, v₂ = velocity of the heavier bullet.
Given: m₂ = 6.5 g = 6.5/1000 = 0.0065 kg, v₂ = 42.0 m/s
Substituting into equation 2,
K₂ = 1/2(0.0065)(42)²
K₂ = 11.466/2
K₂ = 5.733 J.
(c)
The ratio: K₂/K₁ = 5.733/2.205
K₂/K₁ = 2.6.
Answer;
A. the distance that the force move
Explanation;
Simple machines function to make work easier by reducing human effort. These machines may increase the strength of the force, or increase the distance over which the force applied or even change the direction in which the force is applied.
Therefore, when these simple machine reduce strength of a force then the distance over which the force is applied or moves should be increased. Examples of machines that makes work easier by increasing the distance over which the force is applied include, hammers and leaf rakes.