A contour line represents a certain vertical height above the contour line shown. They are means of representing 3D hills and moutains on 2D paper.
Answer:
Option A. 40 mi/h
Explanation:
To obtain the average speed of the vehicle, we'll begin by calculating the distance travelled by the vehicle in each case. This is illustrated below:
Case 1:
Speed = 30 mi/h
Time = 2 h
Distance =...?
Speed = Distance /Time
30 = Distance /2
Cross multiply
Distance = 30 × 2
Distance = 60 mi
Case 2:
Speed = 60 mi/h
Time = 1 h
Distance =...?
Speed = Distance /Time
60 = Distance /1
Cross multiply
Distance = 60 × 1
Distance = 60 mi
Finally, we shall determine the average speed of the vehicle as follow:
Total distance travelled = 60 + 60
Total distance travelled = 120 mi
Total time = 2 + 1
Total time = 3 h
Average speed =..?
Average speed = Total Distance travelled /Total time
Average speed = 120/3
Average speed = 40 mi/h
Therefore, the average speed of the vehicle is 40 mi/h
Answer:
I think it is D
Explanation:
the Bohr model says that electrons whizz around the atomic nucleus in the same way that the earth goes around the sun - but rather than being bound by gravity, it is bound by electromagnetic forces.
Answer:
B: Energy that is transformed is neither created or destroyed
Explanation:
Answer:
k = 0.5 MN/m
Explanation:
Mass of the railcar, m = 5000 kg
Speed of the rail car, v = 1 m/s
The Kinetic energy(KE) of the railcar is given by the equation:
KE = 0.5 mv²
KE = 0.5 * 5000 * 1²
KE = 2500 J
The spring's compression, x = 0.1 m
The potential energy(PE) stored in the spring is given by the equation:
PE = 0.5kx²
PE = 0.5 * k * 0.1²
PE = 0.005k
According to the principle of energy conservation, Kinetic energy of the railcar equals the potential energy stored in the spring
KE = PE
2500 = 0.005k
k = 2500/0.005
k = 500000 N/m
k = 0.5 MN/m
