Answer: the rider’s pedal force must be greater than friction and the force of gravity
Explanation:
This is because if the pedal force was less, you would go slower, and it is obviously not impossible to ride up a hill without increasing speed. But if the force was greater, your speed would increase.
When a large rock is weathered into tiny pieces which add up the weight of the original rock, this demonstrates the law of conservation of matter.
According to this law the mass of an object doesn't change with time and also it does not depends on how the particles are arranged themselves.
Hence, option (C) is correct.
Answer:
Natalie says that all things with mass have a gravitational field, but the force is very weak and cannot be perceived around small objects.
Explanation:
The force due to gravity is proportional to the mass of the object and inversely proportional to the square of the distance between objects. The Earth is so massive that the force due to its gravity is much greater than the force between objects on the counter.
If there were no friction, the objects might move toward each other, depending on what other masses were near them tending to cause them to move in other directions.
Natalie's explanation is about the best.
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<em>Additional comment</em>
The universal gravitational constant was determined by Henry Cavendish in the late 18th century using lead balls weighing 1.6 pounds and 348 pounds. His experiment was enclosed in a large wooden box to minimize outside effects. While these masses are somewhat greater than those of a glue bottle and stapler, the experiment shows the force of gravity between "small" objects <em>can</em> be measured.
Answer:
B=9.1397*10^-4 Tesla
Explanation:
To find the velocity first we put kinetic energy og electron is equal to potential energy of electron
K.E=P.E
where :
m is the mass of electron
v is the velocity
V is the potential difference
eq 1
Radius of electron moving in magnetic field is given by:
eq 2
where:
m is the mass of electron
v is the velocity
q=e=charge of electron
B is the magnitude of magnetic field
Put v from eq 1 into eq 2
B=9.1397*10^-4 Tesla
