<span>Correct Answer: Option B
The complete question is:
A train starts from rest and accelerates uniformly until it has traveled 3.7 km and acquired a velocity of 30m/s The train then moves at a constant velocity of 30m/s for 410 s. The train then slows down uniformly at 0.065m/s</span>²<span> until it reaches a halt. What distance does the train travel while it is slowing down?
We have the initial velocity u = 30 m/s
Final velocity = v = 0
Acceleration = a = -0.065 m/s</span>²
The negative sign indicates that the train is slowing down.
Using the 3rd equation of motion, we can find the distance covered by the train:
2as = v² - u²
2(-0.065)S = 0 -30²
⇒
S = 6923 meters = 6.9 km
Answer:
A.Adding energy
Explanation:
Frequency is directly related to energy
More energy means more frequency
Answer:
100 A.
Explanation:
From the question given above, the following data were obtained:
Electrochemical equivalent (Z) = 0.0012 g/C
Mass (M) = 36 g
Time (t) = 5 mins
Current (I) =?
Next, we shall determine the charge. This can be obtained as follow:
Electrochemical equivalence (Z) = 0.0012 g/C
Mass (M) = 36 g
Charge (Q) =.?
M = ZQ
36 = 0.0012 × Q
Divide both side by 0.0012
Q = 36 / 0.0012
Q = 30000 C
Next, we shall convert 5 mins to s. This can be obtained as follow:
1 min = 60 s
Therefore,
5 mins = 5 × 60
5 mins = 300 s
Finally, we shall determine the current. This can be obtained as shown below:
Charge (Q) = 30000 C
Time (t) = 300 s
Current (I) =?
Q = It
30000 = I × 300
Divide both side by 300
I = 30000 / 300
I = 100 A
Therefore, the current is 100 A.
OK, the wedge is accelerating (a) at Theta = 180 degrees (to the right) and the wedge is inclined theta = 75 degrees. For the m = 2 kg block to remain at rest all we need is a net force f = W cos(theta) - F sin(theta) = 0; where F = ma and W = mg the weight of the block. That is, the weight component along the incline is offset by the acceleration component along the surface; so the block does not slide.
Solving we have W cos(theta) = mg cos(theta) = ma sin(theta) = F sin(theta); such that a = g cos(theta)/sin(theta) = g cot(theta). Assuming g ~ 9.81 m/sec^2, you can now plug and chug to find the answer.
<span>The physics is this...when the net force on a body is f = 0, that body will not accelerate and start to move if it is already still. So when the block's weight component along the surface of the wedge is offset by the equal but opposite force along the surface of the accelerating wedge, the still block will not move.
I hope my answer has come to your help. Thank you for posting your question here in Brainly.
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