Sound energy cannot travel through A vacuum,a wooden table,polluted air,pond water
1 answer:
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Answer:
1) 3.66 s
2) 124.44 m
3) 3.12 s
Explanation:
Let's start by first listing down the information in the question.
Red Car : 34 m/s
Blue Car: 28 m/s
Distance between them : 22 m
The difference in speed between the cars is: 34 - 28 = 6 m/s
This means that the red car is catching up to the blue car at a speed of 6 m/s.
1) We can solve this by just dividing the distance by the difference in speed. This becomes:
Thus it takes 3.66 seconds for the red car to catch up to the blue car.
2) We know from (1) that it took 3.66 seconds for the red car to catch up. Since the speed it was travelling at is constant, we only need to multiply it by the time from (1) to get the distance.
This becomes:
Thus the red car travels 124.44 m before catching up to the blue car.
3) If the red car starts to accelerate the moment we see it, the time taken to get to the blue car will be less than before. We can find this in a simple way.
We can use the motion equation :
Here s = 22 m
We can take u as the difference in speed. u = 6 m/s
Acceleration a = (2/3) m/s^2
Substituting the these into the equation we get:
Solving this for the variable 't' using the quadratic formula we get the following two answers:
t1 = 3.12 s
t2 = - 21.12 s
Since t2 is not possible, the answer is t1. This means it takes 3.12 seconds for the red car to catch up to the blue.
Answer:
Explanation:
Assume that the distance travelled initially is d.
In order to stop the block you need some external force which is friction.
If we use the law of energy conservation:
a)
Looking at the formula you can see that the mass doesn't affect the distance travelled, as lng as the initial velocity is constant (Which indicates that the force must be higher to push the block to the same speed) therefore the distance is the same.
b) If the velocity is doubled, then the distance travelled is multiplied by 4, because the distance deppends on the square of the velocity.