Answer:
a) 17.49 seconds
b) 13.12 seconds
c) 2.99 m/s²
Explanation:
a) Acceleration = a = 1.35 m/s²
Final velocity = v = 85 km/h = 
Initial velocity = u = 0
Equation of motion

Time taken to accelerate to top speed is 17.49 seconds.
b) Acceleration = a = -1.8 m/s²
Initial velocity = u = 23.61\ m/s
Final velocity = v = 0

Time taken to stop the train from top speed is 13.12 seconds
c) Initial velocity = u = 23.61 m/s
Time taken = t = 7.9 s
Final velocity = v = 0

Emergency acceleration is 2.99 m/s² (magnitude)
Answer:
: It Decreases.
As the spacecraft gets farther and farther from Earth, the gravitational
forces between the spacecraft and the Earth decrease.
Explanation:
All you would do is for a, 10 times 2 is 20 so it would be 20-dB
For b, 10 times 4 is 40 so it would be 40-dB
<span>For c, 10 times 8 is 80 so it would be 80-dB</span>
Answer:
7.68 m
Explanation:
Kinetic energy in ball = elastic energy in spring
KE = EE
½ mv² = ½ kx²
mv² = kx²
x = v √(m / k)
x = (38.5 m/s) √(20.5 kg / 515 N/m)
x = 7.68 m