a body of mass 5kg initially at rest is subjected to a force of 20N. find the kinetic energy acquired by the body at the end of 10s.
m=5kg
F=20N
u=0
t=10s
v=0
acceleration,a=F/m=20/5=4m/s2
v=u+at
v=0+4*10=40m/s
ke=1/2mv2
=1/2*5*40*40
=4000J
It will accelerate at a rate
a = (F/M) = 20/5 = 4 m/s^2.
After t = 10 s, the speed will be
V = a*t = 40 m/s.
Compute the kinetic energy at that time
(1/2) M V^2 = ___ Joules
2000 joules
4000 joules
1/2*5*(40*40)=4000joules
To find the kinetic energy acquired by the body at the end of 10 seconds, we can use the formula for kinetic energy:
Kinetic Energy = 1/2 * mass * velocity^2
In this case, the body is initially at rest, so its initial velocity is 0 m/s. We can then use Newton's second law of motion to find the acceleration experienced by the body:
Force = mass * acceleration
Rearranging the equation, we can solve for acceleration:
acceleration = Force / mass
Plugging in the given values, we have:
acceleration = 20N / 5kg = 4 m/s^2
Now, we can use the equation for motion with constant acceleration:
velocity = initial velocity + acceleration * time
Since the initial velocity is 0 m/s, the equation becomes:
velocity = 0 + 4 m/s^2 * 10s = 40 m/s
Finally, we can substitute the values into the formula for kinetic energy:
Kinetic Energy = 1/2 * 5kg * (40 m/s)^2
Simplifying the equation, we get:
Kinetic Energy = 1/2 * 5kg * 1600 m^2/s^2
Kinetic Energy = 4000 J
Therefore, the kinetic energy acquired by the body at the end of 10 seconds is 4000 Joules.