Answer:
Efficiency of a machine is how well the machine works and what the machine is capable of doing.
Mechanical advantage=Load/Effort.
720/180=4
Angular velocity = (75x2pie)/60
=2.5pie ras^-1
linear velocity(or speed) at end of string, v = radius x angular velocity
v= 0.5 x 2.5pie
v=3.93 ms^-1
tension of string (I beleve is centeral force aplied by string), F= (mv^2)/r
F= (0.2 x 3.93^2)/0.5
F=6.18 N
(sorry if wrong)
The momentum of the second ball was 15 kg.m/s.
<h3>What is inelastic collision?</h3>
In which collision some amount of kinetic energy of the system is lost that called inelastic collision. In purely inelastic collision, two bodies stick together. But principle of conservation of linear momentum is obeyed.
In the given question,
Two balls collide and after collision, the final momentum of the system = 18 kg.m/s.
Initial velocity of 1st ball of mass 3 kg is 1 m/s.
So, Initial momentum of first ball = mass × velocity = (3 kg) × (1 m/s) = 3 kg.m/s.
According to Principle of conservation of linear momentum for this inelastic collision,
Initial momentum of first ball + initial momentum of second ball = final momentum of the system
⇒ initial momentum of second ball = final momentum of the system - Initial momentum of first ball
= 18 kg.m/s - 3 kg.m/s.
= 15 kg.m/s.
Hence, initial momentum of second ball = 15 kg.m/s.
Learn more about momentum here:
brainly.com/question/24030570
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Answer:
Car B reaches car A in 19.7 s.
Explanation:
Hi there!
The equation of the position of an object moving in a straight line at constant acceleration is as follows:
x = x0 + v0 · t + 1/2 · a · t²
Where:
x = position of the object at time t.
x0 = initial position.
v0 = initial velocity.
t = time.
a = acceleration
When both cars meet, their positions are the same. At the meeting point:
position of car A = position of car B
xA = xB
x0A + v0A · t + 1/2 · aA · t² = x0B + v0B · t + 1/2 · aB · t²
Let´s place the origin of the frame of reference at the point where A is located. In that case x0A = 0 and x0B = 2900 m. Since both cars are initially at rest, v0A and v0B = 0. So, the equation gets reduced to this:
1/2 · aA · t² = x0B + 1/2 · aB · t²
If we replace with the data we have and solve for t:
1/2 · 4 m/s² · t² = 2900 m - 1/2 · 11 m/s² · t²
2 m/s² · t² = 2900 m - 5.5 m/s² · t²
5.5 m/s² · t² + 2 m/s² · t² = 2900 m
7.5 m/s² · t² = 2900 m
t² = 2900 m / 7.5 m/s²
t = 19.7 s
Car B reaches car A in 19.7 s.