if a body of a mass 4kg is acted upon at constant force of 12n at 2sec,calculate the kenetic energy gain by the body.
S= ut+1/2at =0 x t + 1/2 x 3 x (2)2 =6m :k.e=W= f x s= 12 x6=72j
A=f/m, =12/4 =3ms-^1
A=∆v/t, =3/1=∆v/2 cross multiply.
Ans=6ms-^2
Hence.1/2mv^2
1/2×4×6^2= 72J.
YES
S=ut+1/2at=0 xt+1×3×(2)2=6m :k.e=w=f×s=12×6=72j
162
To calculate the kinetic energy gained by the body, we can use the formula:
Kinetic Energy = (1/2) * mass * velocity^2
First, we need to find the velocity of the body. We can use Newton's second law of motion, which states that the acceleration of an object is directly proportional to the net force applied on it and inversely proportional to its mass. The formula is:
Force = mass * acceleration
Rearranging the formula, we have:
acceleration = Force / mass
Substituting the given values, we get:
acceleration = 12 N / 4 kg = 3 m/s^2
Next, we can use the kinematic equation:
velocity = initial velocity + (acceleration * time)
Since the body starts from rest, the initial velocity is 0. Plugging in the values, we have:
velocity = 0 + (3 m/s^2 * 2 s) = 6 m/s
Finally, we substitute the values of mass (4 kg) and velocity (6 m/s) into the kinetic energy formula:
Kinetic Energy = (1/2) * 4 kg * (6 m/s)^2
= (1/2) * 4 kg * 36 m^2/s^2
= 72 Joules
Therefore, the kinetic energy gained by the body is 72 Joules.