Answer:
180,000
Explanation:
Frequency is a quantity that is measured in Hertz [Hz] and it represents the number of rotations per second.
A motor with a frequency of 50 Hz will rotate 50 times per second.
Since we don't want to know how many times it rotates per second, but per hour. The first step is to find how many seconds there are in an hour and then multiply that amount by 50.
Seconds in an hour:
there are 60 seconds per minute, and 60 minutes per hour, thus there are
60*60 = <u>3,600 seconds in an hour</u>
We know that the motor will rotate 50 times per second so to find the number of rotations in 1 hour = 3,600 seconds we multiply:
50*3,600 = 180,000 rotations
Answer:
The first part can be solved via conservation of energy.
For the second part,
the free body diagram of the car should be as follows:
- weight in the downwards direction
- normal force of the track to the car in the downwards direction
The total force should be equal to the centripetal force by Newton's Second Law.
where 
because we are looking for the case where the car loses contact.
Now we know the minimum velocity that the car should have. Using the energy conservation found in the first part, we can calculate the minimum height.
Explanation:
The point that might confuse you in this question is the direction of the normal force at the top of the loop.
We usually use the normal force opposite to the weight. However, normal force is the force that the road exerts on us. Imagine that the car goes through the loop very very fast. Its tires will feel a great amount of normal force, if its velocity is quite high. By the same logic, if its velocity is too low, it might not feel a normal force at all, which means losing contact with the track.
Answer:
a. stay the same for very long
Explanation:
It is rare for any motion to stay the same for a very long time. The force applied on a body causes changes in the magnitude of motion.
- For motion to remain constant, there must not be a net force acting on the body
- All the forces on the body must be balanced.
- This is very hard to come by.
- Motion changes very frequently.
Correct question is;
1/0.12 = (1/0.05) + (1/d')
Answer:
d' = -1/700
Explanation:
1/0.12 = (1/0.05) + (1/d')
Let's rearrange to get;
(1/d') = (1/0.12) - (1/0.05)
(1/d') = (1/(12/100)) - (1/(5/100))
(1/d') = 100/12 - 100/5
Let's multiply through by 60 to get rid of the denominators on the right side;
> (1/d') = 500 - 1200
> (1/d') = -700
> d' = -1/700
Answer:
42.9 μF
Explanation:
V = 3.50 V, Q = 150 μC
C = Q/V = 150/3.50 μF = 42.9 μF
