a steel block has a mass of 40g.it is in the form of a cube. each edge is 1.74cm long. calculate the density

Consider a basketball player spinning a ball on the tip of a finger. If a player performs 1.91 J1.91 J of work to set the ball s

Black_prince [1.1K]

Answer:

ω = 4.07 rad/s

Explanation:

By conservation of the energy:

W = ΔK

$1.91J = I/2*\omega^2$

where $I = 2/3*m*R^2=0.23kg.m^2$

Solving for ω:

$\omega = \sqrt{W*2/I} =4.07rad/s$

7 0

2 years ago

What results when energy is transformed while juggling three bowling pins?

Nady [450]

Answer:

his is an example of the transformation of gravitational potential energy into kinetic energy

Explanation:

The game of juggling bowling is a clear example of the conservation of mechanical energy,

when the bolus is in the upper part of the path mechanical energy is potential energy; As this energy descends, it becomes kinetic energy where the lowest part of the trajectory, just before touching the hand, is totally kinetic.

At the moment of touching the hand, a relationship is applied that reverses the value of the speed, that is, now it is ascending and the cycle repeats.

Therefore this is an example of the transformation of gravitational potential energy into kinetic energy

8 0

1 year ago

Tara is giving a speech on the how to get a U.S. passport for the first time. During her speech, she tells the audience the requ

Alchen [17]

Answer:

a. 1. she informed the audience when she was concluding

2. She simply outlined the steps tying her conclusion to the topic

3. her conclusion was concise and simple.

b. 13.1 grams

Explanation:

a. signalling the end of a speech prepares the mind of the audience and leaves them satisfied, and Kara correctly signaled the end of her speech when she said "In conclusion".

Also, Kara summarized the ideas in her speech by simply outlining the requirements needed to get a U.S passport.

Her conclusion was concise and simple which is very important especially for lengthy speeches because the audience at this point must be getting tired and distracted.

b. Amount of cholesterol in 100 mL of blood = 248 mg

Total Volume of blood = 5.3 Liters.

the question is asking us to find the total grams of cholesterol in the individual's body, that is the total grams of cholesterol in 5.3 Liters of the individuals blood.

To solve, let us use the following steps:

1. unify the units of measuring volume.

since the first volume is given in Milliliters, I will convert the second volume (5.3 Liters) to milliliters too. To do this, note that:

1 liter = 1000 Milliliter (mL)

∴ 5.3 Liters = 5.3 × 1000 = 5300 Milliliters (mL)

2. Calculate the amount of cholesterol in 5300 mL.

100 mL = 248 mg of cholesterol

∴ 1 mL = $\frac{248}{100\\}$ = 2.48 mg

∴ 5300 mL = 2.48 × 5300 = 13,144 mg of cholesterol.

3. Convert the amount of cholesterol from Milligram to gram

Since the question asked for the gram of cholesterol, not the milligram of cholesterol, converting from milligram to gram, we use the following steps:

1000 mg = 1 g

∴ 1 mg = $\frac{1}{1000}$ g

∴ 13144 mg = 13144 × $\frac{1}{1000}$ = $\frac{13144}{1000}$ = 13.144 ≅ 13.1 g of cholesterol ( 1 decimal place).

I suggest you go and study the conversion relationships between the sub units milli, micro, centi and deci.

7 0

2 years ago

A 5 kg object near Earth's surface is released from rest such that it falls a distance of 10 m. After the object falls 10 m, it

makkiz [27]

Answer:D

Explanation:

Given

mass of object $m=5 kg$

Distance traveled $h=10 m$

velocity acquired $v=12 m/s$

conserving Energy at the moment when object start falling and when it gains 12 m/s velocity

Initial Energy $=mgh=5\times 9.8\times 10=490 J$

Final Energy $=\frac{1}{2}mv^2+W_{f}$

$=\frac{1}{2}\cdot 5\cdot 12^2+W_{f}$

where $W_{f}$ is friction work if any

$490=360+W_{f}$

$W_{f}=130 J$

Since Friction is Present therefore it is a case of Open system and net external Force is zero

An open system is a system where exchange of energy and mass is allowed and Friction is acting on the object shows that system is Open .

4 0

2 years ago

The brake in most cars makes use of a hydraulic system. This system consists of a fluid filled tube connected at each end to a p

Maksim231197 [3]

Answer:

The force at the brake pad = 250 N

Explanation:

The hydraulic brake system works on the Pascal's Principle for pressure transmission in fluids; the pressure applied to a fluid is transmitted undiminished in all directions.

For hydraulic systems, the pressure applied to the brake pedal is transmitted undiminished through the fluid filled tube, connected at each end to a piston, to the brake pad.

Hence, mathematically,

P(brake pedal) = P(break pad)

Pressure is given as the force applied divided by the cross sectional Area perpendicular to the direction of applied force.

P(brake pedal) = (Force applied on the brake pedal) ÷ (Cross Sectional Area of the brake pedal)

Force applied on the brake pedal = 50 N

Cross Sectional Area of the brake pedal = 3 cm²

P(brake pedal) = (50/3) = 16.67 N/cm²

P(brake pad) = P(brake pedal) = 16.67 N/cm²

P(brake pad) = (Force applied on the brake pad) ÷ (Cross Sectional Area of the brake pad)

Force applied on the brake pad = F = ?

Cross Sectional Area of the brake pad = 15 cm²

16.67 = (F/15)

F = 16.67 × 15 = 250 N

Hence, the force at the brake pad = 250 N

Hope this Helps!!!

7 0

2 years ago