A block of weight 7.0N rest on a level floor. The frictional force between the block and the floor is 1.0N, A horizontal force of 1.4N is used to pull the block for 4s.what is the velocity of the block after this time?
M*g = 7 N.
M = 7/g = 7/9.8 = 0.71 kg
a = (Fap-Ff)/M = 1.4-1)/0.71=0.56 m/s^2
V = Vo + a*t = 0 + 0.56*4 = 2.24 m/s
To find the velocity of the block after 4 seconds, we need to apply Newton's second law of motion:
1. Calculate the net force acting on the block:
Net force = Applied force - Frictional force
= 1.4N - 1.0N
= 0.4N
2. Calculate the acceleration of the block using Newton's second law of motion:
Net force = Mass * Acceleration
We know that weight = mass * gravity, and weight is given as 7.0N.
Therefore, the mass of the block = weight / gravity
Assuming gravity is 9.8 m/s^2:
Mass = 7.0N / 9.8 m/s^2
≈ 0.71 kg
Net force = Mass * Acceleration
0.4N = 0.71 kg * Acceleration
Acceleration = 0.4N / 0.71 kg
≈ 0.56 m/s^2
3. Use the formula for uniform acceleration to find the final velocity:
Final velocity = Initial velocity + (Acceleration * Time)
Since the block is initially at rest, the initial velocity is 0 m/s.
Time = 4 s (given)
Final velocity = 0 + (0.56 m/s^2 * 4 s)
= 2.24 m/s
Therefore, the velocity of the block after 4 seconds is approximately 2.24 m/s.
To calculate the velocity of the block after a certain time, we will use the equation of motion:
v = u + at
Where:
v = final velocity
u = initial velocity (assumed to be zero since the block is at rest)
a = acceleration
t = time
In this case, we need to determine the acceleration of the block. The net force acting on the block can be calculated using Newton's second law:
Fnet = ma
The force acting in the horizontal direction is the applied force minus the frictional force:
Fnet = 1.4N - 1.0N = 0.4N
Since the weight of the block is given as 7.0N, we can calculate the acceleration by dividing the net force by the mass of the block:
Fnet = ma
0.4N = m * a
However, we are not given the mass of the block. Without knowing the mass, we cannot calculate the acceleration and subsequently the velocity. Please provide the mass of the block in order to proceed with the calculation.