If the object's <em>velocity is constant</em> ... (it's speed isn't changing AND it's moving in a straight line) ... then the net force on the object is zero.<em> (D)</em>
Either there are no forces at all acting on the object, OR there are forces on it but they're 'balanced' ... when you add up all of their sizes and directions, they just exactly cancel each other out, and they have the SAME EFFECT on the object as if there were no forces at all.
Answer:
B) A planet's speed as it moves around the sun will not be the same in six months.
Explanation:
A planet's speed as it moves around the sun will not be the same in six months, is a statement that CANNOT be supported by Kepler's laws of planetary motion.
Answer:
T = 92.8 min
Explanation:
Given:
The altitude of the International Space Station t minutes after its perigee (closest point), in kilometers, is given by:
Find:
- How long does the International Space Station take to orbit the earth? Give an exact answer.
Solution:
- Using the the expression given we can extract the angular speed of the International Space Station orbit:
- Where the coefficient of t is angular speed of orbit w = 2*p / 92.8
- We know that the relation between angular speed w and time period T of an orbit is related by:
T = 2*p / w
T = 2*p / (2*p / 92.8)
Hence, T = 92.8 min
Answer:
62.64 RPM.
Explanation:
Given that
m= 4.6 g
r= 19 cm
μs = 0.820
μk = 0.440.
The angular speed of the turntable = ω rad/s
Condition just before the slipping starts
The maximum value of the static friction force =Centripetal force
Therefore the speed in RPM will be 62.64 RPM.
Answer:
9.98 × 10⁻⁹ C
Explanation:
mass, m = 1.00 × 10⁻¹¹ kg
Velocity, v = 23.0 m/s
Length of plates D₀ = 1.80 cm = 0.018 m
Magnitude of electric field, E = 8.20 × 10⁴ N/C
drop is to be deflected a distance d = 0.290 mm = 0.290 × 10⁻³ m
density of the ink drop = 1000 kg/m^3
Now,
Time =
or
Time =
or
Time = 6.9 × 10⁻⁴ s
Now, force due to the electric field, F = q × E
where, q is the charge
Also, Force = Mass × acceleration
q × E = 1.00 × 10⁻¹¹ × a
or
a =
Now from the Newton's equation of motion
where,
d is the distance
u is the initial speed
a is the acceleration
t is the time
or
or
q = 9.98 × 10⁻⁹ C