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A 0.25 kg ball is at rest on the ground when a kid comes up and kicks it with a horizontal force of 5.1 N. What is the speed of the ball after it has moved 1.5 m?

User Nira
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Final answer:

To determine the speed of the ball after being kicked, the work-energy principle is used, and it is found that the speed of the ball after moving 1.5 meters is 7.82 m/s.

Step-by-step explanation:

To find the speed of the ball after it has been kicked and moved 1.5 meters, we can use the work-energy principle.

The work done by the force is equal to the change in kinetic energy of the ball. The work W done by the force is the product of the force F and the distance d over which it acts:

W = F × d

The change in kinetic energy (ΔKE) is the difference between the final kinetic energy (KEf) and the initial kinetic energy (KEi), which is zero since the ball starts from rest:

ΔKE = KEf - KEi = KEf - 0

The final kinetic energy of the ball can be expressed as:

KEf = \(\frac{1}{2}mv^2\)

Thus, the work done is equal to the final kinetic energy:

W = \(\frac{1}{2}mv^2\)

To find the final speed v of the ball, we solve for v:

v = \(\sqrt{\frac{2W}{m}}\) = \(\sqrt{\frac{2Fd}{m}}\)

Plugging in the given values:

v = \(\sqrt{\frac{2 × 5.1 N × 1.5 m}{0.25 kg}}\)

= \(\sqrt{\frac{15.3}{0.25}}\)

= \(\sqrt{61.2}\) m/s

The final step is to calculate the result:

v = 7.82 m/s

Therefore, the speed of the ball after moving 1.5 meters is 7.82 m/s.

User Thomas Desert
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