An old wheat-grinding wheel in a museum actually works. The sign on the wall says that the wheel has a rotational acceleration o
1 answer:
You might be interested in
Answer:
Circle
Explanation:
When a charged particle is in motion in a region with magnetic field, the particle experiences a force whose magnitude is given by
where
q is the charge
v is the velocity of the particle
B is the strength of the magnetic field
is the angle between the directions of v and B
In this problem, the velocity of the particle is perpendicular to the magnetic field, so
and the formula reduces to
Also, the direction of this force is perpendicular to the direction of motion of the particle. This means that as the charge moves in the region of the magnetic field, the force acting on it acts as a centripetal force: therefore, the particle will start moving by unifom circular motion, with constant speed (because the magnetic force does no work on the particle, since it is perpendicular to the direction of motion).
So, the path of the particle will be a circle.
Answer:
Titan takes 11.634 times longer to orbit Saturn as compared to Enceladus.
Explanation:
We have been given that the average distance of Enceladus from Saturn is 238,000 km; the average distance of Titan from Saturn is 1,222,000 km.
We will use Kepler's Law to solve our given problem.
Upon substituting our given values, we will get:
Taking square root of both sides, we will get:
This implies that time period of Titan about Sturn is 11.634 times more compared to time period of Enceladus about Saturn.
So, basically Titan takes 11.634 times longer to orbit Saturn as compared to Enceladus.
Answer:
A) v₁ = 10.1 m/s t₁= 4.0 s
B) x₂= 17.2 m
C) v₂=7.1 m/s
D) x₂=7.5 m
Explanation:
A)
- Assuming no friction, total mechanical energy must keep constant, so the following is always true:
- Choosing the ground level as our zero reference level, Uf =0.
- Since the child starts from rest, K₀ = 0.
- From (1), ΔU becomes:
- In the same way, ΔK becomes:
- Replacing (2) and (3) in (1), and simplifying, we get:
- In order to find v₁, we need first to find h, the height of the slide.
- From the definition of sine of an angle, taking the slide as a right triangle, we can find the height h, knowing the distance that the child slides down the slope, x₁, as follows:
Replacing (5) in (4) and solving for v₁, we get:
- As this speed is achieved when all the energy is kinetic, i.e. at the bottom of the first slide, this is the answer we were looking for.
- Now, in order to finish A) we need to find the time that the child used to reach to that point, since she started to slide at the its top.
- We can do this in more than one way, but a very simple one is using kinematic equations.
- If we assume that the acceleration is constant (which is true due the child is only accelerated by gravity), we can use the following equation:
- Since v₀ = 0 (the child starts from rest) we can solve for a:
- Since v₀ = 0, applying the definition of acceleration, if we choose t₀=0, we can find t as follows:
B)
- Since we know the initial speed for this part, the acceleration, and the time, we can use the kinematic equation for displacement, as follows:
- Replacing the values of v₁ = 10.1 m/s, t₂= 2.0s and a₂=-1.5m/s2 in (10):
C)
- From (6) and (8), applying the definition for acceleration, we can find the speed of the child whem she started up the second slope, as follows:
D)
- Assuming no friction, all the kinetic energy when she started to go up the second slope, becomes gravitational potential energy when she reaches to the maximum height (her speed becomes zero at that point), so we can write the following equation:
- Replacing from (12) in (13), we can solve for h₂:
- Since we know that the slide makes an angle of 20º with the horizontal, we can find the distance traveled up the slope applying the definition of sine of an angle, as follows: