Answer:
66.5N
Explanation:
F = kx
Where F = force
K = spring constant
x = compression
Given
K = 950N/m
x = 7.0cm
F = ?
First convert the compression to meters .
7.0cm = 7.0 x 0.01
= 0.07 meters
Therefore
F = 950 x 0.07
= 66.5N
Answer:
ΔT = 0.02412 s
Explanation:
We will simply calculate the time for both the waves to travel through rail distance.
FOR THE TRAVELING THROUGH RAIL:

FOR THE WAVE TRAVELING THROUGH AIR:

The separation in time between two pulses can now be given as follows:

<u>ΔT = 0.02412 s</u>
Answer:
The coefficient is 0.90
Explanation:
Drawing a diagram makes thing easier, we will assume that the acceleration tends to zero because it start barely moving.

Force = (mass) x (acceleration)
Force = (18 kg) x (3 m/s²) = 54 newtons
As long as you continue pushing the cart with 54 newtons of force,
it will accelerate at 3 m/s².
At the instant you release it, or keep your hands on it but stop pushing,
it will stop accelerating. It'll continue forward at the speed it had when
the 54 newtons of force stopped.
The bimetallic strip in a fire alarm is made of two metals with different expansion rates bonded together to form one piece of metal. Typically, the low-expansion side is made of a nickel-iron alloy called Invar, while the high-expansion side is an alloy of copper or nickel. The strip is electrically energized with a low-voltage current. When the strip is heated by fire, the high-expansion side bends the strip toward an electrical contact. When the strip touches that contact, it completes a circuit that triggers the alarm to sound. The width of the gap between the contacts determines the temperature that will set off the alarm.