Onsider a ball at rest in the middle of a toy wagon. when the wagon is pulled forward, what happens to the ball? why?
1 answer:
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Answer:
-2.5 m/s²
Explanation:
The acceleration of a body is the change in it's velocity with time.
The change in velocity with time can be obtained as the slope of a velocity time graph ;
Acceleration = (change in velocity / change in time)
Taking the slope :
Change in Velocity = △y = y2 - y1
Change in time = △x = x2 - x1
(10, 15) ; (0, 40)
△y / △x = y2 - y1 / x2 - x1 = (40 - 15) / (0 - 10)
△y / △x = 25 / - 10 = - 2.5 m/s²
Answer:
82.76m
Explanation:
In order to find the distance of the steel ring to the ground, when its temperature has raised by 1°C, you first calculate the radius of the steel tube before its temperature increases.
You use the formula for the circumference of the steel ring:
(1)
C: circumference of the ring = 40000 km = 4*10^7m (you assume the circumference is the length of the steel tube)
you solve for r in the equation (1):
Next, you use the following formula to calculate the change in the length of the tube, when its temperature increases by 1°C:
(2)
L: final length of the tube = ?
Lo: initial length of the tube = 4*10^7m
ΔT = change in the temperature of the steel tube = 1°C
α: thermal coefficient expansion of steel = 13*10^-6 /°C
You replace the values of the parameters in the equation (2):
With the new length of the tube, you can calculate the radius of a ring formed with the tube. You again solve the equation (1) for r:
Finally, you compare both r and r' radius:
r' - r = 6,366,280.484m - 6,366,197.724m = 82.76m
Hence, the distance to the ring from the ground is 82.76m