#18). (I think. It's the one that starts with "Compare..." Gravity ALWAYS attracts. The force between electric charges can attract or repel ... it depends whether the charges are the same kind or opposite kinds.
#19). With both gravity and electric charges, the force between them quickly becomes weaker when the distance between them increases.
#20). I don't think it changes. If the doorknob gets charged by something that TOUCHES it, so that charges can flow into it from the other object or out of it, then the total amount of electric charge on it might change. But the question says that the doorknob is charged by an "electric field", so nothing touched it, and charges couldn't flow into it or out of it. The only way it got charged was by the charges it already had in it getting moved around ... electrons in one part of the knob moving over to the other side. Then it would act as if it was charged ... if you touched it, you might get zapped.
#21)., #22)., #23). You're supposed to draw a graph to answer these. It's a very easy graph to draw, and you should do it. Label the x-axis 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12. Label the y-axis 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2 . Put the four points on the graph ... A, B, C, and D. For each point, the 'battery voltage' is the number on the x-axis and the 'Current' is the number on the y-axis. Then draw a line through the points. When you have the graph to look at, you can easily answer 21, 22, and 23.
24). I'm not sure, and I don't want to guess.
25). Did you ever move a coil of wire near a magnet in class ? This is the same situation, only the magnet is moving and the wire is still. The result will be the same.
26). Magnets have two poles that attract the opposite kind and repel. Now you copy the map and fill in the other side.
This is a lot of work for 5 points, so I left some parts for you to do. Another reason I did that is: You'll learn a lot more that way.
Suppose a NASCAR race car rounds one end of the Martinsville Speedway. This end of the track is a turn with a radius of approximately 57.0 m . If the track is completely flat and the race car is traveling at a constant 30.5 m/s (about 68 mph ) around the turn.
Required:
a. What is the race car's centripetal (radial) acceleration?
b. What is the force responsible for the centripetal acceleration in this case?
O normal
O gravity
O friction
O weight
Answer:
question a
question b
correct option is option 3
Explanation:
From the question we are told that
The radius is
The constant speed at which the race car is travelling is
Generally from the question we are told that the track is completely flat so the only force pulling the car to the middle is the frictional force hence the centripetal force is due to the frictional force
Generally the centripetal acceleration is mathematically represented as
A) Measure the pH of different household chemicals
Explanation:
To demonstrate a chemical property using an experiment, measuring the pH of different household chemicals will be the best way. The pH is the degree of hydrogen or hydroxyl ion concentration in a solution.
Chemical properties tell us about what a substance can do.
It shows if a substance will react with other substances or not.
Examples are flammability, rusting of iron, precipitation, decomposition of water by electric current e.t.c.
Measuring the pH is a chemical property determination procedure.
The pH points to the degree of acidity or alkalinity of a solution.
