Answer:
0
7500J
7500J
Explanation:
Given parameters:
Mass of car = 600kg
Velocity = 5m/s
Unknown:
Original kinetic energy = ?
Final kinetic energy = ?
Work used = ?
Solution:
The kinetic energy of a body is the energy due to the motion of a body.
It can be solve mathematically using expression below;
K.E = m v²
where m is mass
v is velocity
original kinetic energy;
The car started at rest and v = 0, therefore K.E = 0
Final kinetic energy;
K.E = x 600 x 5² = 7500J
Work done:
Work done = Final K.E - Initial K.E = 7500 - 0 = 7500J
Answer:
B. W is positive and a is negative
Explanation:
As we know that the angular speed of the second clock is in positive direction so as it comes to halt from its initial direction of motion then we have
initial angular velocity is termed as positive angular velocity
now it comes to stop so angular acceleration is taken in opposite to the direction of angular speed
so we will have
so here correct answer is
B. W is positive and a is negative
Answer:
E) are almost circular, with low eccentricities.
Explanation:
Kepler's laws establish that:
All the planets revolve around the Sun in an elliptic orbit, with the Sun in one of the focus (Kepler's first law).
A planet describes equal areas in equal times (Kepler's second law).
The square of the period of a planet will be proportional to the cube of the semi-major axis of its orbit (Kepler's third law).
Where T is the period of revolution and a is the semi-major axis.
Planets orbit around the Sun in an ellipse with the Sun in one of the focus. Because of that, it is not possible to the Sun to be at the center of the orbit, as the statement on option "C" says.
However, those orbits have low eccentricities (remember that an eccentricity = 0 corresponds to a circle)
In some moments of their orbit, planets will be closer to the Sun (known as perihelion). According with Kepler's second law to complete the same area in the same time, they have to speed up at their perihelion and slow down at their aphelion (point farther from the Sun in their orbit).
Therefore, option A and B can not be true.
In the celestial sphere, the path that the Sun moves in a period of a year is called ecliptic, and planets pass very closely to that path.
Answer:
The force that the wire exerts on the electron is
Explanation:
Given that,
Current = 8.60 A
Velocity of electron
Position of electron = (0,0.200,0)
We need to calculate the magnetic field
Using formula of magnetic field
Put the value into the formula
We need to calculate the force that the wire exerts on the electron
Using formula of force
Hence, The force that the wire exerts on the electron is
Answer:
17 m/s south
Explanation:
= Mass of dog = 10 kg
= Mass of skateboard = 2 kg
v = Combined velocity = 2 m/s
= Velocity of dog = 1 m/s
= Velocity of skateboard
In this system the linear momentum is conserved
The velocity of the skateboard will be 17 m/s south as the north is taken as positive