Question

A certain force exerted for 1.2s raises the speed of an object from 1.8m/s to 4.2m/s. Latwr the same force is 2s applied for how much does the speed change in 2s

Answer 1

Let the acceleration produced by the force be "a".

Initial velocity = 1.8 m/s

Final velocity = 4.2 m/s

time taken (t) = 1.2 s

$\(a = \frac{4.2 - 1.8}{1.2}\)$

a = 2 $\(\frac{m}{s^2}\)$

Now,

Time taken = 2 seconds

Change in speed = acceleration × time taken

Change in speed = 2 × 2

Change in speed = 4 m/s

Hence, the change in speed by the same force in 2 seconds = 4 m/s.

Answer 2

Answer:

Explanation:

Let the acceleration produced by the force be "a".

Initial velocity = 1.8 m/s

Final velocity = 4.2 m/s

time taken (t) = 1.2 s

a = 2  

Now,

Time taken = 2 seconds

Change in speed = acceleration × time taken

Change in speed = 2 × 2

Change in speed = 4 m/s

Hence, the change in speed by the same force in 2 seconds = 4 m/s.