An object, moving with velocity 5 m / s, undergoes an acceleration of 1 m / s 2 at time t=0 . If the object has a mass of 1 kg, the kinetic energy ( KE) of the object at time t=5 s is

Question

An object, moving with velocity 5 m / s, undergoes an acceleration of 1 m / s 2 at time t=0 . If the object has a mass of 1 kg, the kinetic energy ( KE) of the object at time t=5 s is (A) KE = 12.5 J (B) KE = 20 J (C) KE = 30 J (D) KE = 50 J

Tardigrade Admin · Accepted Answer

Given, u=5 m / s , a=1 m / s 2 and mass =1 kg. So, velocity after 5 s is given as v=u+ at (Equation of motion) v=5+1 × 5 ⇒ v=10 m / s Kinetic energy of object KE =(1/2) m v2 =(1/2) × 1 ×(10)2=50 J

Q. An object, moving with velocity $5 m / s$ , undergoes an acceleration of $1 m / s^{2}$ at time $t = 0.$ If the object has a mass of $1 k g$ , the kinetic energy ( KE) of the object at time $t = 5 s$ is

KE = 12.5 J

KE = 20 J

KE = 30 J

KE = 50 J

KE = 0 J

Given, $u = 5 m / s, a = 1 m / s^{2}$
and mass $= 1 k g$ .
So, velocity after $5 s$ is given as
$v = u +$ at (Equation of motion)
$v = 5 + 1 \times 5$
$\Rightarrow v = 10 m / s$
Kinetic energy of object
$K E = \frac{1}{2} m v^{2}$
$= \frac{1}{2} \times 1 \times (10)^{2} = 50 J$

Q. An object, moving with velocity 5m/s, undergoes an acceleration of 1m/s2 at time t=0. If the object has a mass of 1kg, the kinetic energy ( KE) of the object at time t=5s is