Answer:
When a particle or a system of particles move in a system where no external force acts, then the total linear momentum of the particle system remains constant.
Explanation:
Given data:
Total mass of the skateboarder, 
Mass of the friend, 
Initial velocity of the skateboarder, 
Initial velocity of the the friend, 
Let the new velocity of the skateboarder when his friend jumps be 
.
From the conservation law of linear momentum,
Answer:
do you have any pictures or any answers we can choose from?
Explanation:
This is an incomplete question.
Answer:
a ) = 381.48 J
b )= 84.25 cm
Explanation:
Kinetic energy of the runner
= 1/2 m v²
= .5 x 66 x 3.4²
= 381.48 J
The final kinetic energy of the runner is zero .
Loss of mechanical energy
= 381.48 J
This loss in mechanical energy is due to action of frictional force .
b )
Let s be the distance of slide
deceleration due to frictional force
= μmg/m
.7 x 66 x 9.8 / 66
a = - 6.86 m s⁻¹
v² = u² - 2 a s
0 = 3.4² - 2x6.86 s
s = 3.4² / 2x6.86
= .8425 m
84.25 cm
Answer:
Object C has the most potential energy.
Between A and B, we do not know which has more potential energy.
Explanation:
We know the object with the most potential energy and this is the object at C.
Potential energy is the energy due to the position of a body above the ground surface.
The higher a body is above ground, the more its potential energy.
Potential energy = mass x acceleration due to gravity x height
So;
Object C has the most potential energy.
Between A and B, we do not know which has more potential energy.
This is because, the height and mass of the objects are not quantified using numbers.
Potential energy is a function of mass and height and acceleration due to gravity but acceleration due gravity is a constant.
5 is fossil fuels I believe
