After a student shoves a book across a flat table, it begins to slow down. Why?
1 answer:
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Answer:
- Bigger mass of planet B
- orbiting closer to planet B
Explanation:
The orbital velocity of the vessel around the planet can be found by equalizing the force of gravity between the vessel and the planet and the centripetal force:
where
G is the gravitational constant
m is the mass of the vessel
M is the mass of the planet
r is the distance between the vessel and the centre of the planet
v is the orbital velocity of the vessel
Re-arranging the formula, we find an expression for v:
We see that:
- the bigger the mass of the planet, M, the bigger the velocity
- the bigger the distance between the vessel and the planet, r, the smaller the velocity
So, the correct choices that increase the orbital velocity are:
- Bigger mass of planet B
- orbiting closer to planet B
Answer:
Winner wins by 0.969 s
Explanation:
For the Porche:
Given:
Displacement of Porsche s = 400 m
Acceleration of Porsche a = 3.4 m/s^2
From Newton's second equation of motion,
(u = 0 as the car was initially at rest)
Substituting the values into the equation, we have
= 235.29 / 3.4
t = 15.33 s
For the Honda:
Displacement of Honda = 310 m
Acceleration of Honda = 3 m/s^2
Applying Newton's second equation of motion
(u = 0 for same reason)
Substituting the values into the equation, we obtain
= 620 / 3
t = 14.37 s
Hence
The winner (honda) wins by a time interval of = 15.33 - 14.37
=0.969 s