Answer:
1.6s
Explanation:
Given that A 1.20 kg solid ball of radius 40 cm rolls down a 5.20 m long incline of 25 degrees. Ignoring any loss due to friction,
To know how fast the ball will roll when it reaches the bottom of the incline, we need to calculate the acceleration at which it is rolling.
Since the frictional force is negligible, at the top of the incline plane, the potential energy = mgh
Where h = 5.2sin25
h = 2.2 m
P.E = 1.2 × 9.8 × 2.2
P.E = 25.84 j
At the bottom, K.E = P.E
1/2mv^2 = 25.84
Substitutes mass into the formula
1.2 × V^2 = 51.69
V^2 = 51.69/1.2
V^2 = 43.07
V = 6.56 m/s
Using the third equation of motion
V^2 = U^2 + 2as
Since the object started from rest,
U = 0
6.56^2 = 2 × a × 5.2
43.07 = 10.4a
a = 43.07/10.4
a = 4.14 m/s^2
Using the first equation of motion,
V = U + at
Where U = 0
6.56 = 4.14t
t = 6.56/4.14
t = 1.58s
Therefore, the time the ball rolls when it reaches the bottom of the incline is approximately 1.6s
Answer: 20 minutes
Explanation:
Given the following :
Average speed of train = 120km/hr
Distance = 40km.
The time take by the train moving at an average speed of 120km/hr to cover a distance of 40km due is ;
Recall:
Speed = distance / time
Therefore,
Time taken = distance covered / speed
Time taken = 40km / 120km/hr
Time taken = 1/ 3 hr
Therefore, 1/3 rd of an hour equals
1/3 × 60 = 20 minutes.
Time taken) 20 minutes
Answer:
The ultimate determinant of truth in science is the execution of scientific experiments that prove or discredit a certain scientific statement. It was through scientific experiments that gravity was accepted scientifically.
Explanation:
Gravity was first observed by Isaac Newton, who quickly created theories and calculations to prove it and show that it exists, in addition to showing the influences it has on life and on the planet.
However its existence was discredited by several people, including men of science. Therefore, it was necessary to search for facts, calculations and evidence of its existence, so that it could be accepted and studied more and more deeply. The result of this, was the elaboration of diverse experiences that submitted the gravity to the most different tests until its existence was impossible to be denied.
Explanation:
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