What is the value of the net electrostatic force on (a) particle 1 and (b) particle 2 due to the other particles

A child of mass 40.0 kg is in a roller coaster car that travels in a loop of radius 7.00 m. at point a the speed of the car is 1

pav-90 [236]

I attached the missing picture.
The force of seat acting on the child is a reaction the force of child pressing down on the seat. This is the third Newton's law. The force of a child pressing down the seat and the force of the seat pushing up on the child are the same.
There two forces acting on the child. The first one is the gravitational force and the second one is centrifugal force. In this example, the force of gravity is always pulling down, but centrifugal force always acts away from the center of circular motion.
Part A
For point A we have:
$F_a=F_cf-F_g$
In this case, the forces are aligned, centrifugal is pointing up and gravitational is pulling down.
$F_a=m\frac{v^2}{r}-mg=179 $N$
Part B
At the point, B situation is a bit more complicated. In this case force of gravity and centrifugal force are not aligned. We have to look at y components of this forces, y-axis, in this case, is just pointing upward.
$F=F_{cf}\cos(30)-mg=m\frac{v^2}{r}\cos(30)-mg=153.2$N$
Part C
The child will stay in place at point A when centrifugal force and force of gravity are in balance:
$F_g=F_{cf}\\
mg=m\frac{v^2}{r}\\
gr=v^2\\
v=\sqrt{gr}=8.29\frac{m}{s}$

6 0

2 years ago

Select the correct answer.

natali 33 [55]

The wave speed completely depends on the characteristics and properties of the medium . . . physical properties for mechanical waves, electrical properties for electromagnedtic waves.

So if you want to change the speed of a wave, you have to change the medium . . . shoot it through some different kind of stuff. <em>(B) </em>

4 0

3 years ago

Read 2 more answers

A solar reflector is made using 31 identical triangular-shaped mirrors, each having sides . What is the total surface area of th

Stels [109]

Complete Question

Question 18 (3 points) Solve the problem. (3 points) A solar reflector is made using 31 identical triangular-shaped mirrors, each having sides 2.4m, 2. 3m, 1.5 m. What is the total surface area of the reflector?

A) 33 m2

B) 86 m2

C) 52 m2

D) 34 m2

Answer:

The value is $Area =2.78 \ m^2$

Explanation:

From the question we are told that

The sides are a = 2.4 m

b = 2.3 m

c = 1.5 m

Generally the semi perimeter is mathematically represented as

$s = \frac { a + b + c }{2 }$

=> $s = \frac { 2.4 + 2.3 + 1.5 }{2 }$

=> $s =3.1 \ m$

Generally the using Heron's formula we have that the surface are a is mathematically represented as

$Area = \sqrt{S (S - a) (S - b )(S - c ) }$

=> $Area = \sqrt{3.1 (3.1 - 2.4) (3.1 - 2.3 )(3.1 - 1.5 ) }$

=> $Area =2.78 \ m^2$

6 0

2 years ago

A ball with a mass of 2000 g is floating on the surface of a pool of water. What is the minimum volume that the ball could have

Doss [256]

Answer:

$2000\; {\rm cm^{3}}$ .

Explanation:

When the ball is placed in this pool of water, part of the ball would be beneath the surface of the pool. The volume of the water that this ball displaced is equal to the volume of the ball that is beneath the water surface.

The buoyancy force on this ball would be equal in magnitude to the weight of water that this ball has displaced.

Let $m(\text{ball})$ denote the mass of this ball. Let $m(\text{water})$ denote the mass of water that this ball has displaced.

Let $g$ denote the gravitational field strength. The weight of this ball would be $m(\text{ball}) \, g$ . Likewise, the weight of water displaced would be $m(\text{water})\, g$ .

For this ball to stay afloat, the buoyancy force on this ball should be greater than or equal to the weight of this ball. In other words:

$\text{buoyancy} \ge m(\text{ball})\, g$ .

At the same time, buoyancy is equal in magnitude the the weight of water displaced. Thus:

$\text{buoyancy} = m(\text{water}) \, g$ .

Therefore:

$m(\text{water})\, g = \text{buoyancy} \ge m(\text{ball})\, g$ .

$m(\text{water}) \ge m(\text{ball})$ .

In other words, the mass of water that this ball displaced should be greater than or equal to the mass of of the ball. Let $\rho(\text{water})$ denote the density of water. The volume of water that this ball should displace would be:

$\begin{aligned}V(\text{water}) &= \frac{m(\text{water})}{\rho(\text{water})} \\ &\ge \frac{m(\text{ball}))}{\rho(\text{water})} \end{aligned}$ .

Given that $m(\text{ball}) = 2000\; {\rm g}$ while $\rho = 1.00\; {\rm g\cdot cm^{-3}}$ :

$\begin{aligned}V(\text{water}) &\ge \frac{m(\text{ball}))}{\rho(\text{water})} \\ &= \frac{2000\; {\rm g}}{1.00\; {\rm g\cdot cm^{-3}}} \\ &= 2000\; {\rm cm^{3}}\end{aligned}$ .

In other words, for this ball to stay afloat, at least $2000\; {\rm cm^{3}}$ of the volume of this ball should be under water. Therefore, the volume of this ball should be at least $2000\; {\rm cm^{3}}\!$ .

3 0

1 year ago

Some of the following statements regarding heat exchangers is (are) wrong, namely (A) Heat exchangers are devices where two movi

DaniilM [7]

Answer:

A,B,D,E are wrong

(A) Heat exchangers are devices where two moving fluid streams are mixed together (B) Heat exchangers are devices where two moving fluid streams exchange mass (D) Heat exchangers are devices where two moving fluid streams exchange mechanical work without mixing together (E) There is no heat transfer between the two fluids of an insulated heat exchanger

Explanation:

A heat exchanger can be regarded as a system that bring about transfer heat between two or more than two fluids. It can function in cooling process and heating processes, the fluids involves in this process can have a solid wall to separate them so as to prevent mixing, direct contact could also be utilized. The mechanism is making hot gas jets which could fire upward over a glowing water that is passing through pipes, as water moves along the pipe, heat energy is been absorbed and there is heating up i.e heat is transferred. One is cooked the other is heated up. It is very essential to insulate the whole steam system along with heat exchangers so that energy could be saved and the temperature of the surface would be at safe-to-touch range and also steam quality could be maintained. The types of heat exchanger we have are;

✓Shell and tube heat exchangers.

✓Condensers, evaporators, and boilers

✓Double pipe heat exchangers.

✓Plate heat exchangers.

It should be noted Heat exchangers are devices where two moving fluid streams exchange heat (thermal energy) without mixing together

3 0

2 years ago