What is the kinetic energy of an object with a mass of $7 k g$ $7 kg$ that has been in freefall for $3 s$ $3 s$ ?

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Answer 1 · 2016-05-12T08:39:44

Kinetic Energy $K E = 3025.26$ $KE=3025.26" "$ joules

The given data are as follows
mass $m = 7$ $m=7" "$ kg
time $t = 3$ $t=3" "$ seconds

Assuming it starts from rest at $v_{0} = 0$ $v_0=0$

$v_{f} = v_{0} + g \cdot t$ $v_f=v_0+g*t$

$v_{f} = 0 + (- 9.8) (3)$ $v_f=0+(-9.8)(3)$

$v_{f} = - 29.4$ $v_f=-29.4" "$ m/sec

Kinetic Energy

$K E = \frac{1}{2} m v^{2}$ $KE=1/2mv^2$

$K E = \frac{1}{2} \cdot 7 \cdot {(- 29.4)}^{2}$ $KE=1/2*7*(-29.4)^2$

$K E = 3025.26$ $KE=3025.26" "$ joules

God bless...I hope the explanation is useful.

What is the kinetic energy of an object with a mass of 7 kg7kg7 kg that has been in freefall for 3 s3s3 s?