Answer:
<h2>
187,500N/m</h2>
Explanation:
From the question, the kinectic energy of the train will be equal to the energy stored in the spring.
Kinetic energy = 1/2 mv² and energy stored in a spring E = 1/2 ke².
Equating both we will have;
1/2 mv² = 1/2ke²
mv² = ke²
m is the mass of the train
v is the velocity of then train
k is the spring constant
e is the extension caused by the spring.
Given m = 30000kg, v = 4 m/s, e = 4 - 2.4 = 1.6m
Substituting this values into the formula will give;
30000*4² = k*1.6²

The value of the spring constant is 187,500N/m
Answer:
Explanation:
Average speed is given by
Total distance/ total time taken
So we need to know the distance in the first travel
Then
First part
Speed=60miles/hour
Time 3hours
Distance = speed × time
Distance = 60×3
Distance = 180 miles
Second part
Speed 45mile/hour
And time is 2hours
Distance = speed × time
Distance = 45× 2
Distance = 90miles
So total distance travelled for both cases is 90+180=270miles
And total time is 5hours
Then,
Average speed = total distance/total time
A.S=270/5
A.S= 54miles/hour
Answer:
Answer is C. Both technicians A and B.
Refer below.
Explanation:
Two technicians are discussing the testing of a catalytic converter. Technician A says that a vacuum gauge can be used and observed to see if the vacuum drops with the engine at 2500 RPM for 30 seconds. Technician B says that a pressure gauge can be used to check for backpressure. The following technician is correct:
Both technicians A and B