Answer:
The moment arm is 0.6 m
Explanation:
Given that,
First force 
Second force 
Distance r = 0.2 m
We need to calculate the moment arm
Using formula of torque

So, Here,

We know that,
The torque is the product of the force and distance.
Put the value of torque in the equation


Where,
=First force
=First force
=Second force
= distance
Put the value into the formula


Hence, The moment arm is 0.6 m
Explanation:
Given parameters:
Distance hopped = 84m
Displacement = 84m due east
Time = 7s
Unknown:
Speed of kangaroo = ?
Velocity of kangaroo = ?
Solution:
To solve this problem,
Speed =
=
= 12m/s
Velocity =
=
= 12m/s due east
Conserve natural resources, energy and landfill space.
Answer:
v = 7.67 m/s for L= 1m
Explanation:
Let's use the conservation of mechanical energy, at the highest point and the lowest point
Initial. Vertical ruler
Em₀ = mg h
Final. Just before touching the floor
= K = ½ I w²
Em₀ = 
m g h = ½ I w²
The moment of inertia of a ruler that turns on one end is
I = 1/3 m L²
Let's replace
m g h = ½ (1/3 m L²) w²2
g h = 1/6 L² w²
They ask for the speed of the end so the height h is equal to the length of the ruler
g L = 1/6 L² w²
The linear and angular variables are related
v = w r
w = v / r
In this case the point of interest a in strangers r = L
g L = 1/6 L² v² / L²
v = √ 6 g L
Let's calculate
Assume that the length of the meter is L = 1 m
v = √ (6 9.8 1)
v = 7.67 m/s