A body of mass 10kg is acted on by a constant force of 20n for 3 second calculate the kinetic energy at the end of the time
a = F/m = 20/10 = 2 m/s^2
d = (1/2) a t^2 = (1/2)(1) (3*3) = 9 meters
work done = force * distance = 10 * 9 = 90 Joules
gain in kinetic energy = work done
To calculate the kinetic energy of an object, we need to use the formula:
Kinetic Energy = (1/2) * mass * velocity^2
Given that:
Mass (m) = 10 kg
Force (F) = 20 N
Time (t) = 3 s
First, we need to calculate the acceleration (a) using Newton's second law of motion, which states that the force acting on an object is equal to the mass of the object multiplied by its acceleration:
F = m * a
Rearranging the equation to solve for acceleration:
a = F / m
Substituting the given values:
a = 20 N / 10 kg
a = 2 m/s^2
Next, we need to calculate the final velocity (v) using the equation of motion:
v = u + a * t
where u is the initial velocity. Assuming the initial velocity is 0, since the object starts from rest:
v = a * t
v = 2 m/s^2 * 3 s
v = 6 m/s
Now we can calculate the kinetic energy:
Kinetic Energy = (1/2) * m * v^2
Kinetic Energy = (1/2) * 10 kg * (6 m/s)^2
Kinetic Energy = 180 J
Therefore, the kinetic energy of the object at the end of three seconds is 180 joules (J).
To calculate the kinetic energy at the end of the given time, we need to use the equation:
Kinetic Energy (KE) = 0.5 * mass * velocity^2
First, we need to find the final velocity of the body. We can do that using Newton's second law of motion:
Force = mass * acceleration
Rearranging the equation, we get:
acceleration = Force / mass
Substituting the given force and mass values:
acceleration = 20 N / 10 kg = 2 m/s^2
Next, we need to find the final velocity after 3 seconds. We can use the equation:
velocity = initial velocity + (acceleration * time)
Since there is no initial velocity given, we can assume it is zero, so the equation simplifies to:
velocity = acceleration * time
Substituting the given acceleration and time values:
velocity = 2 m/s^2 * 3 s = 6 m/s
Now, we can substitute this velocity value into the kinetic energy equation:
KE = 0.5 * mass * velocity^2
= 0.5 * 10 kg * (6 m/s)^2
= 0.5 * 10 kg * 36 m^2/s^2
= 180 J
Therefore, the kinetic energy at the end of the 3-second time period is 180 Joules.