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If a 4.5 kg object is dropped from a height of 6.0 m, what will be its velocity when it is halfway toward the ground? (Use g = 9.80 m/s2, and ignore air resistance.) 7.7 m/s 11 m/s 16 m/s 29 m/s

Respuesta :

Catya
When an object falls or is dropped from rest it's initial velocity is zero.
Using the equations for a motion in straight line. I can find the time it takes to reach 3.0 m down (half way).
x = vt - 4.9t²
-3 = 0 - 4.9t²
-3/-4.9 = t²
0.6122 = t²
0.7825 sec = t

v = v - gt
v = 0 - 9.8(0.7825)
v = -7.67 m/s
the negative denotes downward direction.

You  could also solve the problem using potential and kinetic energy.

Since it starts with maximum PE and gets converted to KE when it hits the ground. mgh = mv²/2
mass cancels, use 3 meters for the halfway distance
-9.8(-3) = v²/2
29.4 * 2 = v²
√(58.8) = 7.67 m/s downwards
snehashish65

The velocity  of object at halfway is 7.67 m/s.

Given data:

The mass of object is, m = 4.5 kg.

The height from the ground is, h = 6.0 m.

When an object falls or is dropped from rest it's initial velocity is zero.

(u = 0). Using the second kinematic equations for a motion, find the time it takes to reach 3.0 m down (half way).

x = ut - 1/2gt²

x = ut - 1/2 (9.8) t²

x = ut - 4.9t²

-3 = 0 - 4.9t²

-3/-4.9 = t²

0.6122 = t²

0.7825 sec = t

Now, apply the first kinematic equation of motion as,

v = u + (-g)t

v = 0 - 9.8(0.7825)

v = -7.67 m/s

the negative denotes downward direction.

Thus, we can conclude that the velocity of object at halfway is 7.67 m/s.

Learn more about the kinematic equation of motion here:

https://brainly.com/question/11298125

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