Answer:
The fireman will continue to descend, but with a constant speed.
Explanation:
In kinetic friction <em>(which is the case discussed here) </em>since the fireman is already in motion because of a certain force, once the frictional force matches the normal force, the fireman will stop accelerating and continue moving at a constant rate with the original speed he had. We will need a force greater than the normal force acting on the fireman to cause a deceleration.
We need to understand the difference between static friction and kinetic friction.
Static friction occurs in objects that are stationary, while kinetic friction occurs in objects that are already in motion.
In static friction, when the frictional force matches the weight or normal force of the object, the object remains stationary.
While in kinetic friction, when the frictional force matches the normal force, the object will stop accelerating. This is the case of the fireman sliding down the pole as discussed above.
<u>Momentum</u>
- a vector quantity; has both magnitude and direction
- has the same direction as object's velocity
- can be represented by components x & y.
Find linebacker momentum given m₁ = 120kg, v₁ = 8.6 m/s north
P₁ = m₁v₁
P₁ = (120)(8.6)
[ P₁ = 1032 kg·m/s ] = y-component, linebacker momentum
Find halfback momentum given m₂ = 75kg, v₂ = 7.4 m/s east
P₂ = m₂v₂
P₂ = (75)(7.4)
[ P₂ = 555 kg·m/s ] = x-component, halfback momentum
Find total momentum using x and y components.
P = √(P₁)² + (P₂)²
P = √(1032)² + (555)²
[[ P = 1171.77 kg·m/s ]] = magnitude
!! Finally, to find the magnitude of velocity, take the divide magnitude of momentum by the total mass of the players.
P = mv
P = (m₁ + m₂)v
1171.77 = (120 + 75)v <em>[solve for v]</em>
<em />v = 1171.77/195
v = 6.0091 ≈ 6.0 m/s
If asked to find direction, take inverse tan of x and y components.
tanθ = (y/x)
θ = tan⁻¹(1032/555)
[ θ = 61.73° north of east. ]
The magnitude of the velocity at which the two players move together immediately after the collision is approximately 6.0 m/s.
Answer:
You drop a rock from rest out of a window on the top floor of a building, 30.0 m above the ground. When the rock has fallen 3.00 m, your friend throws a second rock straight down from the same window. You notice that both rocks reach the ground at the exact same time. What was the initial velocity of the ...... rest out of a window on the top floor of a building, 30.0m above the ground. ... You Notice That Both Rocks Reach The Ground At The Exact Same Time. ... You drop a rock from rest out of a window on the top floor of a building, 30.0m ... When the rock has fallen 3.20 m, your friend throws a second rock straight down from ...
Answer and Explanation:
The main source of earth magnetic field is the metals and iron present in earth crust these metals are mainly found in liquid state in earth crust and we know that whenever there is spinning of these liquid metals then there will magnetic field generate, So the main source of earth magnetic field is the metals present in earth crust.
KE = 2000 J
Explanation:
KE = (1/2)mv^2
= (1/2)(0.100 kg)(200 m/s)^2
= 2000 J
