Answer:
25.71 kgm/s
Explanation:
Let K₁ and K₂ be the initial and final kinetic energies of object A and v₁ and v₂ its initial and final speeds.
Given that K₂ = 0.7K₁
1/2mv₂² = 0.7(1/2mv₁²)
v₂ = √0.7v₁ = √0.7 × 20 m/s = ±16.73 m/s
Since A rebounds, its velocity = -16.73 m/s and its momentum change, p₂ = mΔv = m(v₂ - v₁) = 0.7 kg (-16.73 - 20) m/s = 0.7( -36.73) = -25.71 kgm/s.
Th magnitude of object A's momentum change is thus 25.71 kgm/s
Answer:
V = 3.17 m/s
Explanation:
Given
Mass of the professor m = 85.0 kg
Angle of the ramp θ = 30.0°
Length travelled L = 2.50 m
Force applied F = 600 N
Initial Speed u = 2.00 m/s
Solution
Work = Change in kinetic energy
Answer:
d. All of these
Explanation:
work is said to be done when a force is applied to an object through a certain distance. the SI unit of workdone is joules or newton per meter
mathematically
workdone = force x distance.
from the answers, work is being done because there is force applied in a certain distance.
- from wagon is used to carry vegetables from a garden.
- pulley is used to get water from a well.
- hammer is used to remove a nail from a wall.
The bouncy ball experiences the greater momentum change.
To understand why, you need to remember that momentum is actually
a vector quantity ... it has a size AND it has a direction too.
The putty and the ball have the same mass, and you throw them
with the same speed. So, on the way from your hand to the wall,
they both have the same momentum.
Call it " M in the direction toward the wall ".
After they both hit the wall:
-- The putty has zero momentum.
Its momentum changed by an amount of M .
-- The ball has momentum of " M in the direction away from the wall ".
Its momentum changed by an amount of 2M .
