Question

41. If V=3i+4j+5k is the instantaneous velocity of a body of mass 4 kg.
Calculate its kinetic energy? *​

Answer 1

Answer:

If v=(3+4j+5k)m/s is the instantaneous velocity of a body of mass 1.5kg . Calculate its kinetic energy. ... v=(3 i+4 j+5 k)m/s. We Know, ... ahlukileoi and 41 more users found this answer helpful.

Answer 2

Answer:

If velocity is V=3i+4j+5k and the mass of the body is 4 kg, its kinetic energy is 99.8J

Explanation:

• The kinetic energy of a particle with mass (m) with velocity (v) is equal to

        $KE=\frac{1}{2}mv^{2}$

• If vector A is $A=ai+bj+ck$ its magnitude is $/A/=\sqrt{a^{2} +b^{2} +c^{2} }$

From the question, we have

mass of the body $m=4kg$

velocity in vector form $v=3i+4j+5km/s$

magnitude of velocity $/v/=\sqrt{3^{2} +4^{2} +5^{2} }$

⇒$/v/=\sqrt{50}=7.07m/s$

now the kinetic energy of the body

$KE=\frac{1}{2} *4*(7.07) ^{2}$

⇒$KE=99.8J$