Answer:
Explanation:
Photon is also a particle . Hence when two particles like electron and positron annihilate to get completely changed to photons , a minimum of two photons of equal and opposite momentum and energy are produced flying in opposite direction to conserve momentum and energy . Each photon will have same energy equal to 511 keV . It is so to conserve momentum and energy. Initially total momentum was zero so finally too total momentum should be zero.
Answer:
F = 4.47 10⁻⁶ N
Explanation:
The expression they give for the strength of the tide is
F = 2 G m M a / r³
Where G has a value of 6.67 10⁻¹¹ N m² / kg² and M which is the mass of the Earth is worth 5.98 10²⁴ kg
They ask us to perform the calculation
F = 2 6.67 10⁻¹¹ 135 5.98 10²⁴ 13 / (6.79 10⁶)³
F = 4.47 10⁻⁶ N
This force is directed in the single line at the astronaut's mass centers and the space station
Answer:
The objects become oppositely charged and have equal amounts of charge.
Explanation:
There are three methods for charging objects:
- Conduction: a charged object is brought in contact with a neutral object. Electrons are transferred from the charged object to the neutral one, which also becomes charged
- Induction: a charged object is brought close (but not in contact) to a neutral object. The charges inside the neutral object redistribute, such that those of opposite sign to the charge in the charged object migrate on the side closer to the charged object, while the charges of same sign migrate towards the opposite side. If the neutral object is then grounded, the charges on the opposite side flow to the ground, leaving the neutral object charged as well
- Friction: two objects initially neutral are rubbed against each other. Electrons move from one object to the other one: therefore, one object becomes positively charged while the other one becomes negatively charged. Since the charge gained by one object is equal to charge lost by the other object, it follows that the two objects have same magnitude of charge, but with opposite sign.
Let us first calculate the average speed of David,
Av speed = Distance traveled/ Time taken
We have, distance = 70 miles
Time = 
hours = 1.75 hours
Av speed = 
= 40 miles/hour
Another 120 miles will be traveled in time, t = 120/40 = 3 hours
