Answer:
Explanation:
This problem is all about torque. The "rules" are that in order for a system to be in rotational equilibrium, the sum of the torques on the system have to equal 0 (in other words, they have to equal each other {cancel each other out}). The equation for torque is
τ = F⊥r where τ is torque, F⊥ is the perpendicular force, and r is the lever arm length in meters. We also have to understand that in general Forces moving clockwise are negative and Forces moving counterclockwise are positive. Now we're ready for the problem:
A. The counterclockwise torque:
τ = 300(3) so
τ = 900N*m
B. The clockwise torque:
τ = -450(2.5) so
τ = -1100N*m
C. Obviously the system is not in roational equilibrium because one side is experiencing a greater torque than the other. This system will move clockwise as it currently exists.
D. In order for the system to be in rotational equilibrium, we have to move Bob's location from the fulcrum. Let's see to where.
The torques have to be the same on both sides of the fulcrum; mathematically, that looks like this:
F⊥r = F⊥r Filling in:
300(3) = 450r and
900 = 450r so
2 = r. This means that Bob will have to move closer to the fulcrum by a half of a meter to 2 meters from the fulcrum in order for the system to be in balance.
Isn't this so much fun?!
Answer: 5.075Ns
Explanation:
Given the following :
Mass of ball = 145g
Initial Speed of ball = 15m/s
Final speed of ball when hit by the batter = - 20m/s ( Opposite direction)
The impulse of a body is represented using the relation:
Force(f) * time(t) = mass (m) * (final Velocity(V) - initial velocity(u))
Therefore, using:
m(v - u) = impulse
Mass of ball = 145 / 1000 = 0.145kg
Impulse = 0.145(- 20 - 15)
Impulse = 0.145(-35)
Impulse = 5.075Ns
Explanation:
Suppose the cheetah is initially positioned at x=0 (m) from the reference, and the gazelle is intially at poisiton x=d (m).
Then, at the worst case, that is when cheetah is running at the maximum case, the position of the gazelle relative to the reference must be larger than that of cheetah.
In equation form,
Answer:
R = 0.1 ohms
Explanation:
It is given that,
Voltage of the battery, V = 12.5 V
Current flowing in the car's starter, I = 125 A
We need to find the effective resistance of a car's starter. It can be calculated using Ohm's law. Let R is the resistance.
So, the resistance of the car's starter is 0.1 ohms.
