Answer:
26b) 66.7%
27) 500 N
Explanation:
26.a) In a two pulley system, the load is attached to one of the pulleys. The other pulley is attached to a fixed surface, as well as one end of the rope. The other end of the rope goes around moving pulley, then around the fixed pulley.
26.b) Mechanical advantage is the ratio between the forces:
MA = load force / effort force
Efficiency is the ratio between the work:
e = work done on load / work done by effort
Work is force times distance.
e = (F load × d load) / (F effort × d effort)
Rearranging:
e = (F load / F effort) × (d load / d effort)
e = MA × (d load / d effort)
In a two pulley system, the load moves half the distance of the effort. So the efficiency is:
e = (4/3) × (1/2)
e = 2/3
e = 66.7%
27) In a three pulley system, the load moves a third of the distance of the effort.
e = (F load / F effort) × (d load / d effort)
0.40 = (600 N / F) × (1/3)
F = 500 N
Answer: meter per second
Explanation: meter per second
Speed has the dimensions of distance divided by time. The SI unit of speed is the meter per second, but the most common unit of speed in everyday usage is the kilometer per hour or, in the US and the UK, miles per hour. For air and marine travel the knot is commonly used.
Answer:
The distance between the ships is 87.84 km.
Explanation:
Given that,
Angle of first ship= 40°
Speed of first ship = 18 knots
Angle of second ship= 130°
Speed of second ship = 26 knots
We need to calculate the resultant velocity
Using cosine rule
Put the value into the formula
We need to calculate the distance between the ships
Put the value into the formula
Hence, The distance between the ships is 87.84 km.
(a) 
<u>Explanation:</u>
Given:
Moment of Inertia of m₁ about the axis, I₁ = m₁x²
Moment of Inertia of m₂ about the axis. I₂ = m₂ (L - x)²
Kinetic energy is rotational.
Total kinetic energy is 
Work done is change in kinetic energy.
To minimize E, differentiate wrt x and equate to zero.
Alternatively, work done is minimum when the axis passes through the center of mass.
Center of mass is at 
Answer:
0 Newtons
Explanation:
The velocity of the object does not change, it is a constant 54 km/hr. When velocity does not change, acceleration is zero. Using the formula Force = mass x acceleration, we find:
mass = 1200 kg
acceleration = 0
F = (1200)(0) = 0
