To show your friends how strong you are, you start pushing a big container with mass 50 kg along a long, flat highway. While you are pushing the container in a horizontal direction with an average force 350 N, it moves with acceleration 1 m/s/s. After 5 seconds of pushing you give up and stop pushing. Find values of as many variables or physical quantities as you can.
Fn = ma = 50 * 1`= 50N. = Net force.
Fap - Fk = Fn,
350 - Fk = 50,
Fk = 350 - 50 = 300N = Force of kinetic friction.
Fap = Force applied.
d = Vo*t + 0.5a*t^2,
d = 0 + 0.5*%^2 = 12.5m.
Work = Fd = 350 * 12.5 = 4375 Joules.
Power = F*d/t=4375/5= 875J/s=875Watts.
Correction: d = 0 + 0.5*5^2 = 12.5m.
To find the values of the variables or physical quantities, we will use the relevant equations from Newton's second law of motion.
1. Mass (m) of the container: Given as 50 kg.
2. Average Force (F): Given as 350 N.
3. Acceleration (a): Given as 1 m/s².
4. Time (t): Given as 5 seconds.
5. Initial Velocity (u): We assume the initial velocity is zero since the container is initially at rest.
Now, let's use the equations:
1. Newton's Second Law equation:
F = ma
Substituting the given values:
350 N = 50 kg * 1 m/s²
Therefore, the equation is satisfied.
2. To find the Final Velocity (v):
We can use the equation of motion:
v = u + at
Since the initial velocity (u) is zero:
v = 0 + (1 m/s²) * 5 s
v = 5 m/s
Therefore, the container reaches a final velocity of 5 m/s after 5 seconds.
3. Work Done (W):
Work is given by the formula:
W = F * d
Since the force (F) and acceleration (a) are constant over the distance (d), we can use the equation:
W = F * d
Rearranging the equation, we can solve for distance (d):
d = W / F
Since the average force (F) was exerted for 5 seconds:
d = (350 N * 5 s) / 350 N
d = 5 m
Therefore, the container was pushed a distance of 5 meters.
To summarize, the values of the variables or physical quantities are as follows:
- Mass (m) of the container: 50 kg
- Average Force (F): 350 N
- Acceleration (a): 1 m/s²
- Time (t): 5 seconds
- Initial Velocity (u): 0 m/s
- Final Velocity (v): 5 m/s
- Distance (d) covered: 5 meters