All categories

3 years ago

How many forces are acting on a stationary raft floating in a swimming pool A1 B2 or C3

1 answer:

3 0

There are at least two forces on it, and there could be more.

Vertical forces:
-- gravity, directed downward
-- buoyant force, directed upward
These two forces must be exactly equal, so that the net
vertical force on the raft is zero. Otherwise, it would be
accelerating either up or down.

Horizontal forces:
We know that the net horizontal force on the raft is zero.
Otherwise, it would be accelerating horizontally.

But we don't know if there are actually no horizontal forces
at all, or a balanced group of horizontal forces, that add up
to a net force of zero.

You might be interested in

A hollow cylinder with an inner radius of 5 mm and an outer radius of 26 mm conducts a 4-A current flowing parallel to the axis

bearhunter [10]

Answer:

B = 38.2μT

Explanation:

By the Ampere's law you have that the magnetic field generated by a current, in a wire, is given by:

$B=\frac{\mu_o I_r}{2\pi r}$ (1)

μo: magnetic permeability of vacuum = 4π*10^-7 T/A

r: distance from the center of the cylinder, in which B is calculated

Ir: current for the distance r

In this case, you first calculate the current Ir, by using the following relation:

$I_r=JA_r$

J: current density

Ar: cross sectional area for r in the hollow cylinder

Ar is given by $A_r=\pi(r^2-R_1^2)$

The current density is given by the total area and the total current:

$J=\frac{I_T}{A_T}=\frac{I_T}{\pi(R_2^2-R_1^2)}$

R2: outer radius = 26mm = 26*10^-3 m

R1: inner radius = 5 mm = 5*10^-3 m

IT: total current = 4 A

Then, the current in the wire for a distance r is:

$I_r=JA_r=\frac{I_T}{\pi(R_2^2-R_1^2)}\pi(r^2-R_1^2)\\\\I_r=I_T\frac{r^2-R_1^2}{R_2^2-R_1^2}$ (2)

You replace the last result of equation (2) into the equation (1):

$B=\frac{\mu_oI_T}{2\pi r}(\frac{r^2-R_1^2}{R_2^2-R_1^2})$

Finally. you replace the values of all parameters:

$B=\frac{(4\pi*10^{-7}T/A)(4A)}{2\PI (12*10^{-3}m)}(\frac{(12*10^{-3})^2-(5*10^{-3}m)^2}{(26*10^{-3}m)^2-(5*10^{-3}m)^2})\\\\B=3.82*10^{-5}T=38.2\mu T$

hence, the magnitude of the magnetic field at a point 12 mm from the center of the hollow cylinder, is 38.2μT

8 0

3 years ago

The power in an electrical circuit is given by the equation P= RR, where /is

Rainbow [258]

Answer:D

Explanation:Electric power=I*I*R

=12*12*100

=14400watts

6 0

3 years ago

An electron enters the gap between the plates of a capacitor at the center of the gap traveling parallel to theplates at 2.0 x 1

Svetlanka [38]

Answer:

How far will the electron travel beforehitting a plate is 248.125mm

Explanation:

Applying Gauss' law:

Electric Field E = Charge density/epsilon nought

Where charge density=1.0 x 10^-6C/m2 & epsilon nought= 8.85× 10^-12

Therefore E = 1.0 x 10^-6/8.85× 10^-12

E= 1.13×10^5N/C

Force on electron F=qE

Where q=charge of electron=1.6×10^-19C

Therefore F=1.6×10^-19×1.13×10^5

F=1.808×10^-14N

Acceleration on electron a = Force/Mass

Where Mass of electron = 9.10938356 × 10^-31

Therefore a= 1.808×10^-14 /9.11 × 10-31

a= 1.985×10^16m/s^2

Time spent between plate = Distance/Speed

From the question: Distance=1cm=0.01m and speed = 2×10^6m/s^2

Therefore Time = 0.01/2×10^6

Time =5×10^-9s

How far the electron would travel S =ut+ at^2/2 where u=0

S= 1.985×10^16×(5×10^-9)^2/2

S=24.8125×10^-2m

S=248.125mm

4 0

3 years ago

Giving brainly, please help

brilliants [131]

Answer:

when the mug is heated thus its temperature rises increasing the kinetic energy of the molecules , the oscillations around the rest position in the mug(solid) increases which increase the spaces between molecules and the mug expands. what cause the cracking is that outside of the mug expands before the inside and the mug cracks

3 0

3 years ago

Your friend is bragging about his motorcycle. He claims that it can go from a stopped position to 50 miles per hour in three sec

nalin [4]

If the motorcycle can go from 0 to 50mph in 3 seconds the person is describing the motorcycle's acceleration.

8 0

3 years ago

Read 2 more answers