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An object moving with constant acceleration changes its speed from 20 m/s to 60 m/s in 2.0 s. What is the acceleration? (b) How far did it move in this time?

User Bergeroy
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2 Answers

5 votes

Final answer:

The acceleration of an object whose speed changes from 20 m/s to 60 m/s in 2.0 seconds is 20 m/s². The object moved 80 meters during this time.

Step-by-step explanation:

To calculate the acceleration of an object moving with constant acceleration, we use the formula a = ∆v / t, where ∆v is the change in velocity and t is the time taken for this change. In this case, the change in velocity (∆v) is 60 m/s - 20 m/s = 40 m/s. Given that this change occurs over a period of 2.0 seconds, the acceleration a would be 40 m/s / 2.0 s = 20 m/s².

Next, to find out how far the object moved in this time, we can use the formula for displacement under constant acceleration, s = ut + 0.5at², where u is the initial velocity, a is the acceleration, and t is time. Substituting our values, we get s = (20 m/s)(2.0 s) + 0.5(20 m/s²)(2.0 s)² = 40 m + 40 m, which results in the object moving a distance of 80 meters.

User Mertez
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6.2k points
4 votes

Answer:

a)
20\ \rm m/s^2

b) 80 m

Step-by-step explanation:

Given:

  • Initial velocity of the object, u=20 m/s
  • Final velocity of the object, v=60 m/s
  • Time taken, t=2 s

Using Equation of motion we have

a)Let a be the acceleration of the object


v=u+at\\60=20+2a\\a=20\ \rm m/s^2

b) Let d be the distance covered by the object given by

Using equation of motion we have


2ad=v^2-u^2\\2*20* d=60^2-20^2\\d=80\ \rm m

User Crizant
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6.3k points