In a perfectly ELASTIC collision between two perfectly rigid objects <span>both the momentum and the kinetic energy of the system are conserved.hope it helps</span>
Answer:
Making the crossing gate balanced makes the mechanical drive simpler and less expensive to operate.
Explanation:
See the attachment for a picture of what we're talking about.
The gate must be rotated up and down. That rotation is easier if the mass being rotated is balanced about the center of rotation. Less torque (and work) is required to create the desired motion.
Hi there!
Recall:
Impulse = Change in momentum
I = Δp = mΔv = m(vf - vi)
Let the direction TOWARDS the floor be POSITIVE, and AWAY be NEGATIVE.
Plug in the givan values:
Δp = 1.5(-10 - 12) = -33 Ns
**OR, the magnitude: |-33| = 33 Ns
Answer:
The speed of the police car is 294 m/s
Explanation:
Given;
frequency of the siren in air, f = 280 Hz
speed of sound in air, v = 343 m/s
Determine the wavelength of the sound in air to the stationary car:
v = fλ
where;
λ is wavelength of the sound
λ = v/f
λ = 343 / 280
λ = 1.225 m
Now, determine the speed at which the police car is approaching the stationary car;
The actual frequency of the police car, F = 240 Hz
V = Fλ
Where;
V is speed of the police car
λ is the distance between the police car and the stationary car, (wavelength)
V = 240 x 1.225
V = 294 m/s
Therefore, the speed of the police car is 294 m/s
