A 200N force acts on a 30kg mass on a horizontal surface against 50N of friction.
What is the speed of the mass after 5 seconds?
To find the speed of the mass after 5 seconds, we need to use Newton's second law of motion, which states that the force applied to an object is equal to the mass of the object multiplied by its acceleration. The equation to solve for acceleration is:
Force applied - Force of friction = (mass)(acceleration)
Given:
Force applied = 200 N
Force of friction = 50 N
Mass = 30 kg
First, we need to calculate the net force acting on the object:
Net force = Force applied - Force of friction
Net force = 200 N - 50 N
Net force = 150 N
Next, we calculate the acceleration using the formula:
Acceleration = Net force / Mass
Acceleration = 150 N / 30 kg
Acceleration = 5 m/s²
Now that we have the acceleration, we can use the equation of motion to find the speed of the mass after 5 seconds. The equation of motion is:
Final velocity = Initial velocity + (Acceleration x Time)
Given:
Initial velocity = 0 m/s (assuming the object starts from rest)
Time = 5 seconds
Acceleration = 5 m/s²
Plugging the values into the equation of motion:
Final velocity = 0 m/s + (5 m/s² x 5 s)
Final velocity = 0 m/s + 25 m/s
Final velocity = 25 m/s
Therefore, the speed of the mass after 5 seconds is 25 m/s.