Lead has a density of 11. 5 g/cm³. A rectangular block of lead measures 7 cm x 5 cm x 2 cm.
a) Find the volume of the block of lead.
b) Find the mass of the block of lead.

(Please give step-by step explanations as well.)
Thank you!

Answer:

i) v = 1.47 cm/s

ii) distance = 219.8 cm

iii) displacement = 28cm

Explanation:

Remember that:

The motion of the tip of the second hand is a circular motion.

For something that rotates with an angular frequency ω, and a radius R, the velocity is given by:

v = ω*R.

i) We know that the second hand of a clock does a complete rotation each 60 seconds.

Then the period is:

T = 60s

And the frequency is the inverse of the period, so:

f = 1/T

f = (1/60s)

And the angular frequency is 2*pi times the normal frequency, thus:

ω = 2*pi*f

ω = 2*pi*(1/60s)  = (2*pi/60s)

And the radius will be 14 cm, the velocity of the ant is:

v = (2*pi/60s)*14cm

if we replace pi by 3.14 we get:

v =  (2*3.14/60s)*14cm = 1.47 cm/s

ii) The distance covered by the ant in 150 seconds:

Remember that the period of the clock is T = 60s

so in 150 seconds we have:

150s/60s = 2.5 revolutions.

Then the total distance covered is 2.5 times the perimeter of a circle of radius R = 14cm, this is:

distance = (2.5)*2*pi*14cm

              = (2.5)*2*3.14*14cm = 219.8 cm

iii) We want to know the displacement, this is, the difference between the final position and the initial position.

In 150 seconds, the ant does 2.5 revolutions.

So the ant will end in the opposite side of the circle where she started (if the ant started when the second hand was at the "3", then the final position is when the second hand is at the "9").

So the displacement will be equal to twice the radius, or the diameter of the circle.

if the radius is 14cm, the diameter is:

2*14cm = 28cm

the displacement is 28cm

Answer:

Explanation:

Use the one-dimensional equation for motion

v = v₀ + at and filling in,

v = 0 + (-9.8)(3.32) so

v = -33 m/s (negative because it is going downwards and upwards is positive).

Answer:

(a) 477 m

(b) 44.6 s

(c) 21.16 m

(d) 19.24 m

Explanation:

initial speed, u = 77km/h = 21.4 m/s

acceleration, a = - 0.48 m/s2

final speed v =  0  

(a) let the stopping distance is s.

Use third equation of motion

[tex]v^2 = u^2 + 2 a s\\\\0 = 21.4^2 - 2 \times 0.48\times s\\\\s = 477 m[/tex]

(b) Let t is time.

Use first equation of motion

v = u + at

0 = 21.4 - 0.48 t

t = 44.6 s

(c) Let the distance is s in first second.

Use second equation of motion

[tex]s = u t + 0.5 at^2\\\\s = 21.4\times 1 - 0.5\times 0.48\times 1\\\\s = 21.4 - 0.24 = 21.16 m[/tex]

(d) distance traveled in 5 th second is given by

[tex]s = u + 0.5 a (2 n - 1) \\\\s = 21.4 - 0.5\times 0.48 \times (2\times 5 -1)\\\\s= 21.4 - 2.16 = 19.24 m[/tex]

Answer:

weight

Explanation:

Weight is the force of gravity with which a body is attracted towards the earth.

Answer:

Arrange an annual service. Treat your boiler like your car. ...

Keep your boiler clean. ...

Bleed your radiators. ...

Top up the pressure. ...

Use a Powerflush. ...

Insulate your pipes. ...

Turn the heating on. ...

If all else fails…

Explanation:

Answer:

The final velocity of the skier and boat is 0.33 m/s to the east.

Explanation:

We can find the final velocity of the skier by conservation of linear momentum:

[tex] m_{s}v_{s_{i}} + m_{b}v_{b_{i}} = m_{s}v_{s_{f}} + m_{b}v_{b_{f}} [/tex]

Where:  

[tex]m_{s}[/tex]: is the mass of the water skier = 62.0 kg

[tex]m_{b}[/tex]: is the mass of the boat = 775 kg

[tex]v_{s_{i}}[/tex]: is the initial velocity of the skier = 4.50 m/s (as she leaves the dock)

[tex]v_{b_{i}}[/tex]: is the initial velocity of the boat = 0 (it is at rest)

[tex]v_{s_{f}}[/tex]: is the final velocity of the skier =?

[tex]v_{b_{f}}[/tex]: is the final velocity of the boat =?

Since the final velocity of the skier is the same that the velocity of the boat ([tex]v_{f}[/tex]) we have:

[tex] m_{s}v_{s_{i}} + 0 = v_{f}(m_{s} + m_{b}) [/tex]

[tex]v_{f} = \frac{m_{s}v_{s_{i}}}{m_{s} + m_{b}} = \frac{62.0 kg*4.50 m/s}{62.0 kg + 775 kg} = 0.33 m/s                  

Therefore, the final velocity of the skier and boat is 0.33 m/s to the east.

I hope it helps you!                                                          

Well since the gravitational pull is so strong, nothing can escape from it which means we haven't been able to get close enough to really know everything about them. There's no way of knowing what truly goes on inside of them since there is no way out.

Answer:

A black hole is a region of spacetime where gravity is so strong that nothing—no particles or even electromagnetic radiation such as light—can escape from it. The theory of general relativity predicts that a sufficiently compact mass can deform spacetime to form a black hole.

Explanation:

Answer:

A. Object A requires twice the force to stop as Object B.

Explanation:

Inertia can be defined as the tendency of an object or a body to continue in its state of motion or remain at rest unless acted upon by an external force.

Newton's Second Law of Motion states that the acceleration of a physical object is directly proportional to the net force acting on the physical object and inversely proportional to its mass.

Mathematically, it is given by the formula;

[tex] Acceleration = \frac {Net \; force}{mass} [/tex]

Let's assume the following values;

Mass of object B = 10 kg

Mass of object A = 2 * B = 2 * 10 = 20 kg

Acceleration = 5 m/s²

I. To find the force for B;

[tex] Force = mass * acceleration [/tex]

[tex] Force = 10 * 5 [/tex]

Force B = 50 Newton

II. To find the force for A;

[tex] Force = mass * acceleration [/tex]

[tex] Force = 20 * 5 [/tex]

Force A = 100 Newton

From the calculation, we can deduce that Force A (100 N) is twice or double the value of Force B (50 N).

In conclusion, since object A has twice the mass of object B and both objects are moving at the same speed, object A would require twice the force to stop as Object B.

Answer:

-2.5 m/s²

Explanation:

The acceleration of a body is the change in it's velocity with time.

The change in velocity with time can be obtained as the slope of a velocity time graph ;

Acceleration = (change in velocity / change in time)

Taking the slope :

Change in Velocity = △y = y2 - y1

Change in time = △x = x2 - x1

(10, 15) ; (0, 40)

△y / △x = y2 - y1 / x2 - x1 = (40 - 15) / (0 - 10)

△y / △x = 25 / - 10 = - 2.5 m/s²

Answer:

Protein bars

Explanation:

Protein bars contain low-sugar and have high protein content and are therefore good source of nutrient when it is required to take food on-the-go so as to keep the muscle mass the same when it is not possible to take a meal on busy days or before workout

Protein bars can also be taken as part of easy and fast breakfast when travelling so as to maintain a balanced blood sugar level

Answer:

dₒ/dᵢ = 0.32

Explanation:

From the question given above, the following data were obtained:

Object height (Hₒ) = 4 mm

Image height (Hᵢ) = 1.25 cm

Ratio of object distance (dₒ) to image distance (dᵢ) [dₒ/dᵢ] =?

Next, we shall convert 4 mm to cm. This can be obtained as follow:

10 mm = 1 cm

Therefore,

4 mm = 4 mm × 1 cm / 10 mm

4 mm = 0.4 cm

Next, we shall determine the magnification of the lens. This can be obtained as follow:

Object height (Hₒ) = 4 mm

Image height (Hᵢ) = 1.25 cm

Magnification (M ) =?

M = Hᵢ/Hₒ

M = 1.25 / 0.4

M = 3.125

Finally, we shall determine the ratio of object distance (dₒ) to image distance (dᵢ). This can be obtained as follow:

Magnification (M) = 3.125

Ratio of object distance (dₒ) to image distance (dᵢ) [dₒ/dᵢ] =?

Magnification (M) = image distance (dᵢ) / object distance (dₒ)

M = dᵢ/dₒ

Invert

1/M = dₒ/dᵢ

1/3.125 = dₒ/dᵢ

dₒ/dᵢ = 0.32

Therefore, the ratio of object distance (dₒ) to image distance (dᵢ) [dₒ/dᵢ] is 0.32

Answer:

Explanation:

This is a Law of Momentum Conservbation problem, where the total energy of the system cannot increase or decrease, only change form. The total energy equation for this situation is

TE = PE + KE where TE is total energy, PE is potential energy, and KE is kinetic energy. We begin by realizing that the go-kart is motionless at the top of a hill. If the kart isn't moving, then it has no KE, but if it is up off the ground and has the potential to fall to a point lower than it is curremtly, it has potential energy. That means that the total energy available to this go-kart is found in its potential energy and will not change throughout the trip's entirety. Thus,

TE = PE + 0 and

TE = (50.0)(9.8)(10.0) so

TE = 4900 J and since that's the total energy available throughout the trip, and we are looking to find the height of the next hill where this is both potential and kinetic energy, then

4900 = PE + KE and

4900 = (50.0)(9.8)(h) + [tex]\frac{1}{2}(50.0)(1.0)^2[/tex] and

4900 = 490h + 25.0 and

4875 = 490h so

h = 9.9 m (I kinda ignored the rules for significant digits at the end, which goes against every teacher's bone in my body, but nonetheless, there's your answer!)

Answer:

the velocity is zero, the acceleration is directed downward, and the force of gravity acting on the ball is directed downward

Explanation:

Is this exercise in kinematics

          v = v₀ - g t

where g is the acceleration of the ball, which is created by the attraction of the ball to the Earth.

At the highest point

velocity must be zero.

The acceleration depends on the Earth therefore it is constant at this point and with a downward direction.

The force of the earth on the ball is towards the center of the Earth, that is, down

all other alternatives are wrong

Answer:

A cyclotron is a type of particle accelerator.

Explanation:

Cyclotron frequency is the frequency of a charged particle moving perpendicular to the direction of a uniform magnetic field B, since that motion is always circular, the cyclotron frequency is given by equality of centripetal force and magnetic Lorentz force.

2nd egg experienced more impulse

Hope this helps! :)

Answer:

no

Explanation:

the equation can't be balanced because it doesn't have the same elements on each side of the equal sign.

The given equation is not a balanced chemical equation because it does not contain the same elements on both sides of the equation.

A chemical equation can be explained as the representation of a chemical reaction in terms of symbols of the substances. A balanced equation containing the same number of atoms of each element on either side of the equation.

The law of mass conservation is followed by every balanced chemical equation. By obeying this law, the total mass on the reactant side should be equal to the total mass on the product side in a balanced equation.

On both sides of the chemical equation, the same elements as well as an equal number of elements are present as the chemical reaction does not alter the identity of the elements. Therefore, the given equation is not a balanced chemical equation.

Learn more about the balanced chemical equation, here:

brainly.com/question/28294176

#SPJ2

Answer:

Resistance is a measure of the opposition to current flow in an electrical circuit.All materials resist current flow to some degree. They fall into one of two broad categories: Conductors: Materials that offer very little resistance where electrons can move easily.

Answer:

16 s

Explanation:

From the question given above, the following data were obtained:

Mass (m) = 40 Kg

Velocity (v) = 4 m/s

Power (P) = 20 W

Time (t) =?

Next, we shall determine the energy. This can be obtained as follow:

Mass (m) = 40 Kg

Velocity (v) = 4 m/s

Energy (E) =?

E = ½mv²

E = ½ × 40 × 4²

E = 20 × 16

E = 320 J

Finally, we shall determine the time. This can be obtained as follow:

Power (P) = 20 W

Energy (E) = 320 J

Time (t) =?

E = Pt

320 = 20 × t

Divide both side by 20

t = 320 / 20

t = 16 s

Thus, the time is 16 s

Answer:

【 In vector form , if angle between velocity vector and acceleration vector is less than 90° and greater than 0° then it is positive acceleration and if it is less than 180° and greater than 90° then it is negative acceleration. If there is no acceleration vector then it is called zero acceleration. 】

Answer:

-40 feet to the left

Explanation:

opposite of 40 feet from right is -40 to left

Answer:

B. -40 feet to the left

Answer:

it helps me

Explanation:

:))) ...

....

Answer:

152,155 J

Explanation:

115,333 + 36,822 = 152,155J

Answer:

a) the distances are zero, Both 1st & 2nd condition

c)  the torques are equal but of the opposite sign, 2nd condition of equilibrium

Explanation:

The equilibrium conditions are

1 translational

        ∑ F = 0

2 rotational

        ∑ τ = Σ (F_i x r_i) = 0

They tell us that external torque is zero.

Therefore we have two various possibilities

a) the distances are zero, in this case we have a pure translation movement

    for this situation the two equilibrium relations are fulfilled

b) the forces are zero, there is no movement

    It does not make sense to use the equilibrium relations since there are no forces

c) the torques are equal but of the opposite sign, the forces are on the opposite side of the body.

    In this case the 2 equilibrium relation is fulfilled, but not the first one that the force has the same direction

Answer: Milky Way

Explanation:

Answer:

A

Explanation:

transverse wave

Hope this helps you!

Answer:

19m/s

Explanation:

U= 4m/s

a = 0.5m/s²

t= 30s

V= U+at

= 4+15

=19m/s

Answer:

E = 3.8 kJ

Explanation:

Given that,

The mass of the object, m = 10 g = 0.01 kg

The heat of fusion of  aluminum is 380 kJ/kg

We need to find the energy required to melt the mass of the aluminium. It can be calculated as follows:

E = mL

So,

E = 0.01 × 380

E = 3.8 kJ

So, the energy required to melt the mass is equal 3.8 kJ.

Answer:

Please find detailed explanation of second class levers below

Explanation:

Levers are one of the classes of machine that possesses three levels namely: first class, second class and third claas. A second class lever is the level of levers in which the load (L) is in between the pivot (F) and the effort (E).

Examples of second class levers include; wheelbarrow, a bottle opener etc. In the bottle opener for example, the bottle lid (load) is in between the pivot of the opener and the hand opening it (effort).