Question

Power delivered to a body varies as P=3t^2. Find out the change in kinetic energy of a body from t=2 sec to t=4 sec.

Answer 1

Answer on Question #52006, Physics, Mechanics | Kinematics | Dynamics

**Given:**

$N = 3t^{2}$ power

$t_0 = 2s$

$t_1 = 4s$

**Find:**

$\Delta E$

**Solution:**

$$N = \frac{A}{t} \quad A = \Delta E \quad \Rightarrow \quad \Delta E = Nt = 3t^{2} \cdot t = 3t^{3}$$

from $t_0$ to $t_1$:

$$\Delta E = 3t_1^3 - 3t_0^3 = 3(64 - 8)J = 168J$$

**Answer:** $\Delta E = 168J$

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