Question

A train on a straight, level track has an initial speed of 35 m/s. A uniform acceleration of 1.5 m/s² is applied. How long did it take for the train to reach a speed of 70 m/s?

A) 20 seconds
B) 23.33 seconds
C) 30 seconds
D) 40 seconds

Answer 1

The train takes approximately 23.33 seconds to reach a speed of 70 m/s.

Step-by-step explanation:

To find the time it takes for the train to reach a speed of 70 m/s, we can use the equation:

v = u + at

where v is the final velocity, u is the initial velocity, a is the acceleration, and t is the time.

Given:

u = 35 m/s

a = 1.5 m/s²

v = 70 m/s

Let's plug in the values:

70 = 35 + 1.5t

Subtracting 35 from both sides, we get:

35 = 1.5t

Dividing both sides by 1.5, we get:

t = 35 / 1.5

t ≈ 23.33 seconds

Therefore, the answer is B) 23.33 seconds.