All vehicles are required to stop within 15 FEET of the railroad crossing when a train is approaching.
Answer:
The velocity is 19.39 m/s
Solution:
As per the question:
Mass, m = 75 kg
Radius, R = 19.2 m
Now,
When the mass is at the top position in the loop, then the necessary centrifugal force is to keep the mass on the path is provided by the gravitational force acting downwards.


where
v = velocity
g = acceleration due to gravity

B. Ask a question - Hypothesize - Experiment - Analyze - Draw a conclusion
Explanation:
The scientific method is a systematic approach in which investigations are conducted in science.
It follows systematic manner;
- An observation in nature is made using the senses.
- Questions are then asked about such observations. This is the inquiry phase.
- A hypothesis is then formula to predict what might cause the observation.
- Experiments are then conducted
- The results are analyzed and a conclusion is drawn
learn more:
Experiments brainly.com/question/5096428
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Answer:
The magnitude of the force, B = 5 Tesla, Up (North) direction
Explanation:
Magnetic force F= Eq where Electric field, E = 750 NC
and charge, q = -70 μC = -7 ×
C
F = 750 × -7 ×
F = 0.0525
But F = qvB; B = 
where B is the magnetic field
= 0.0525 ÷ ( -7 ×
× 30)
B = 5.0 Teslas
The force on a negative charge is in exactly the opposite direction to that on a positive charge.
Hence the direction of the charge is up (North).
given,
mass of bicyclist(m)=90Kg
centripetal acceleration(a)=1.5 m/s2
centripetal force(F)=ma= 90×1.5=145 N