Answer:
29 seconds
Explanation:
First we have a constant speed of 12 m/s and the distance of 240 m, so to find the time we can use the formula:
distance = speed * time
240 = 12 * time1
time1 = 20 seconds
Then, the speed decreases at 2 m/s2 until it reaches 2 m/s. So to find this time, we use this formula:
Final speed = inicial speed + acceleration * time
2 = 12 - 2 * time2
2*time2 = 10
time2 = 5 seconds.
Then, the speed increases from 2 m/s to 22 m/s with an acceleration of 5 m/s2, so we have:
Final speed = inicial speed + acceleration * time
22 = 2 + 5 * time3
5*time3= 20
time3 = 4 seconds
The total time is:
Total time = time1 + time2 + time3 = 20 + 5 + 4 = 29 seconds
Answer:
Between 2.0 s and 4.0 s (B and C)
Between 5.0 s and 8.0 s (D and E)
Between 10.0 s and 11.0 s (F and G)
Explanation:
The graph shown in the figure is a velocity-time graph, which means that:
- On the x-axis, the time is plotted
- On the y-axis, the velocity is plotted
Therefore, this means that the object is not moving when the line is horizontal (because at that moment, the velocity is constant, so the object is not moving). This occurs in the following intervals:
Between 2.0 s and 4.0 s (B and C)
Between 5.0 s and 8.0 s (D and E)
Between 10.0 s and 11.0 s (F and G)
From the graph, it would be possible to infer additional information. In particular:
- The area under the graph represents the total distance covered by the object
- The slope of the graph represents the acceleration of the object
Answer:
Repulsion
Explanation:
Every magnet has two poles: North and South. Magnets have a property that they attract or repel another magnet and iron-nickel objects. But whether two magnets will attract or repel each other depends on how they are brought together. If unlike poles are brought near the magnets will attract. If like poles are brought near then they will repel each other.
Here north pole of one magnet will repel north pole of another magnet.
Answer:
40N
Explanation:
Using the newton's second law of motion
\sum Fx = max
Fm - Ff = max
Fm is the applied force
Ff is the frictional force
m is the mas of the cupboard
ax is the acceleration
Since the speed from the lorry is steady, ax = 0m/s^2
Also Ff = 40N
Substitute into the formula;
Fm - 40 = m(0)
Fm - 40 = 0
Add 40 to both sides
Fm - 40 + 40 = 0 + 40
Fm = 40N
Hence the force with which the man applied to push is 40N
