Physics High School

## Answers

**Answer 1**

**Answer:**

7.5 minutes (you mean hours)

t = 7.5 min (if it was actually not hours than put minutes just letting u know.)

**Explanation:**

The first thing you have to do is know the equation; it is t = d/s, which is time = distance divided by speed. Know fill in the equation, now it will be t = 750 km/100 km/ hr ( in this min). If you divide it, then the answer will be t = 7.5 min (which it has to be hours instead of min because hours makes more sense than minutes.)

**Answer 2**

The car will take **7.5 hours **to cover a distance of **750km**.

What are Speed and velocity?

**Speed **is defined as the rate over time at which an object is moving along a path, while **velocity **is defined as the rate and direction of motion of an object. **Speed **is a **scalar quantity **as it has only magnitude, no direction but **Velocity **is a **vector quantity **as it has both magnitude as well as direction.

**Speed **can be expressed as:

**Speed= Distance travelled/ Time taken**

**Velocity **can be expressed as:

**Velocity= Displacement travelled/ Time taken**

Both the **quantities **are expressed as **meter per second **(m/s).

If the two values are given , we can calculate the another value like in the above given information, speed of the car = **100km/hr **and distance travelled by the car= **750 km**.

So, Time taken= 750/100 = 7.5 hours

Thus, the car will take **7.5 hours **to cover a distance of **750km**.

Learn more about **Speed and velocity**, here:

https://brainly.com/question/15973714

#SPJ2

## Related Questions

1. How many energy levels do the electrons in an atom of iron occupy?

### Answers

**Electrons in atoms occupy energy levels, also called electron shells, outside the nucleus. Different shells can hold different maximum numbers of electrons. The electrons in an atom occupy the lowest available energy level first.on:**

**Answer:**

26. Brainliest?

**Explanation:**

Iron atoms have 26 electrons and the shell structure is 2.8.

A drunk college student decides to try to do a perfect swan dive from his apartment window into the pool below. The edge of the pool is 5 meters from the base of the building and his window is on the 3rd floor, which is 8 meters from the ground. If he jumps out the window horizontally at a speed of 4 m/s, does he make it into the water or..

### Answers

**Answer:**

He barely makes it but hit his leg on the pool edge.

**Explanation:**

Using kinematic formula: Δx=[tex]v_{0}t+(1/2)at^2[/tex]

We can plug in delta x, v zero, and acceleration.

delta x = 8 meters, v0 = 0. a = 9.8

8=(1/2)9.8*t^2

Around 1.278 seconds of airtime.

4 * 1.278 = 5.112 meters horizontally assuming no air resistance

**That was close!**

Erica forgot to put gas in her car (again) for two weeks. The graph below shows the last few seconds of her car being stalled along Elkins Drive st 7:23 am Friday. During the time shown, what was the acceleration of her car?

a 54 m

b 108 m/s

c 3 m/s^2

D -3 m/s^2

### Answers

**Answer:**

Option (D) : - 3 m/s^2

**Explanation:**

Acceleration = Slope of v-t graph

= 18/6

= - 3 m/s^2 (-ive since the car is decelerating )

Use the picture to answer the question. Name at least three physical properties of the bowling ball.

### Answers

**Answer:**

Density, Color, and Luster.

**Explanation:**

**Density**, describes how compact the matter is in a substance. A bowling ball is more dense than a beach ball. **Color** - Describes how light reflects off a substance. **Luster** - Describes how shiny a substance is.

**Answer:**

The physical properties is hardness shape and color, I choose hardness because I have grabbed bowling balls before and they are very hard well there could be different types of bowling balls made of different things but I have never seen one or toughed a bowling ball that is not hard. Another physical property I chose for the bowling ball was shape, The reason I chose shape was because the bowling ball is circle, the actual name for a 3-D circle is sphere. The last physical property for a bowling ball is color because mostly all bowling balls have color for example the one in the picture it is red with a little bit of pink, there is many different bowling balls that have different color different hardness but NOT different shape. That is the physical properties of a bowling ball.

**Explanation:**

:)

Evidence of a chemical change includes

A)change in size.

B)change in color.

C)change in shape.

Eliminate

D)change in weight.

### Answers

Evidence of a chemical change includes

change in color

A student clicks the mouse at time intervals of 1.60, 2.10, 2.40, 1.90 what is the standard deviation of this dataset.

A. 0.22

B. 0.25

C. 0.29

D. 0.58

### Answers

i hope this helps you

and stay safe

A truck covered 2/7 of a journey at an average speed of 40

mph. Then, it covered the remaining 200 miles at another

average speed. If the average for the whole journey was 35

mph, what was the amount of time for the whole journey?

h

### Answers

Answer:8h

Explanation:

Answer: 8 h

Explanation:

I got it right

a car is driving at 57 mi/hr, how long will it take for the car to go 80 mile

### Answers

**Answer:**

1 hour 6 minutes and about 6 seconds

A 2 kg ball is dropped from the roof of a building 27.5 m tall. How long

does it take to hit the ground?

### Answers

**Answer:**

wow I need time to solve dis

if a object falls from 5 meters how long did it take for it to reach the ground explain(gravity= -10)

### Answers

Idkgfjfjfjriurugucufududu

**Explanation:**

[tex]time \: period = \sqrt{ \frac{2h}{g} } = \sqrt{ \frac{10}{10} } = 1sec[/tex]

An object moves along the x-axis. The graph shows its position x as a function of time t. Find the average velocity of the object from points B to C. −8.3 m/s −4.2 m/s 0 m/s −0.12 m/s

### Answers

**Answer:**

-8.3m/s

**Explanation:**

its correct

**Answer: its 0.**

**Explanation: Gradpoint**

How to keep your community clean

### Answers

**Answer:**

Work with the local civic groups to identify and eliminate eyesores, and beautify the local environment

Pick up a piece of litter every day

Keep a litter bag in your car or your recreational vehicle so you dispose of litter properly

Create a trash fishing contest in your waterway to increase awareness about illegal dumping and littering

Write a letter to the editor of your local newspaper asking others to respect public lands and keep them clean

Help your local schools conduct recycling drives and clean-up projects

Create a beautiful green space by planting trees and shrubs in an area in need of improvement.

Ask local businesses to adopt-a-spot and take care of it

Paint and fix up playground equipment

Organize a paint-out with family and friends and create a community paintbrush mural over a wall of illegal graffiti

Recycle your old tires

Report graffiti to your local authorities

Donate your old computer equipment or dispose of it properly

Conduct a recycling drive in your neighborhood or your business

Volunteer to help your employer conduct paper recycling drives at work

Donate gently used clothes to needy organizations and shelters and identify other items that you can reuse

Compost yard and food waste and seek advice if you don’t know how

Find out how pollution in storm drain runoff can impact our aquifers and ecosystems and be passionate about doing your part to reduce litter and solid waste

Ask your local government officials to establish regular community improvement activities and to support and promote volunteer efforts

Help your library establish an environmental corner that offers books and other educational materials about taking care of the Earth

Help me I need this now

### Answers

**Answer:**

**If the height of the ramp is changed at a different height then the speed of the car will change.**

which sI units are combined to describe force?

### Answers

**Answer:**

Symbol N

**Explanation:**

The SI unit of force is the newton, symbol N

The units of **mass**, **length**, and **time** are.

The combination is the unit of force, called the "Newton".

1 **Newton** is the force that accelerates 1 **kilogram** of mass at the rate of 1 **meter **per **second** every second.

hey can anyone help me out in dis pls

### Answers

**Answer:**

All of the above

**Explanation:**

Solids have a fixed shape and volume.

Even though the molecules in a solid are vibrating, they can't travel from one part of the solid to the other.

I hope this helps! :)

How long should a spring be stretched for it to store 45 J of energy? The force constant of the spring is

540N/m?

### Answers

**Answer:**

x = 0.4 m

**Explanation:**

When a spring is stretched from its equilibrium position. Some energy is stored in the spring. This energy is called the elastic potential energy of the spring. The formula used to calculate the magnitude of this stored energy is given as follows:

**P.E = (1/2)kx²**

where,

P.E = Elastic Potential Energy Stored in the spring = 45 J

k = Spring Constant = 540 N/m

x = amount of stretching = ?

Therefore,

**45 J = (1/2)(540 N/m)x²**

**x² = (45 J)(2)/(540 N/m)**

**x = √(0.167 m²)**

**x = 0.4 m**

When the mass of an object decreases, the force of gravity - Remains Unchanged - Decreases - increases - Becomes irregular

### Answers

**Answer:**

Decreases

**Explanation More mass=More gravitational pull**

**Less mass=Less gravitational pull**

**Hope this helps**

**Answer:**

decreses

**Explanation:**

differenciate between emf and potential difference

### Answers

**Answer: 1.Emf is the total voltage in the battery while the potential difference is the work done in moving a charge against the electric field between two specific points in the circuit. 2.Emf is always greater than the potential difference.**

**Explanation:**

To me (electrical engineer since 1973), there is no difference. They are two different names for the same thing.

3. The value of frictional force on block in the given

diagram is (Take g = 10 m/s2)

5N

m = 3 kg

8.

u = 0.3

(1) 4N

(2) 5 N

(3) 6 N.

(4) 9 N

### Answers

I need help with my homework it’s due tomorrow and I feel like I failed can u help me bro

Which ball has the greater acceleration at the instant of release?

Ball thrown upward or downward

### Answers

They're equal.

Ignoring air resistance, any object you're not holding onto has the same, constant acceleration ... 9.8 m/s^2 down ... from the moment it leaves your hand until the moment it hits the ground.

It doesn't matter how heavy the object is, and it doesn't matter whether you throw it up, down, or sideways, or just let go and let it drop.

Which is a limitation of using cellulose?

its lack of mass production

its lack of biodegradability

3

its harm to landfills

O its high cost to recycle

### Answers

**Answer:**

Its lack of mass production

**Explanation:**

Your Welcome;)

The **limitation **of using **cellulose **is its lack of **mass production**.

**Cellulose **is a polymer of **glucose**. It is obtained from glucose by **condensation polymerizatio**n to yield a long chain.

**Cellulose **materials have a high potential of being quite useful as important materials for diverse applications.

However, the problem with cellulose materials is that they can not really be **mass produced**. This limitation has long encumbered the possibility of using cellulose materials for various applications in material science.

Learn more: https://brainly.com/question/961761

In the lab, you looked at speed-time graphs to determine the acceleration of the cart for each of the three fan

speeds.

What was the acceleration of the cart with Low fan speed?

cm/s2

What was the acceleration of the cart with Medium fan speed? cm/s2

What was the acceleration of the cart with High fan speed?

cm/s2

### Answers

**Answer:**

(I). The acceleration of the cart with low fan speed is 18 cm/s²

(II). The acceleration of the cart with medium fan speed is 23.3 cm/s²

(III). The acceleration of the cart with high fan speed is 32 cm/s²

**Explanation:**

**Given that,**

You looked at speed-time graphs to determine the acceleration of the cart for each of the three fan speeds in the lab.

**According to graph,**

A , B and shows the high, medium and low fan speeds respectively.

**We know that,**

The speed-time graph shows the acceleration.

Acceleration is equal to the rate of change of velocity.

**(I). We need to calculate the acceleration of the cart with low fan speed**

**Using formula of acceleration**

[tex]a_{l}=\dfrac{v_{f}-v_{i}}{t_{f}-t_{i}}[/tex]

Put the value from graph

[tex]a_{l}=\dfrac{125-0}{7}[/tex]

[tex]a_{l}=18\ cm/s^2[/tex]

**(II). We need to calculate the acceleration of the cart with medium fan speed**

**Using formula of acceleration**

[tex]a_{m}=\dfrac{v_{f}-v_{i}}{t_{f}-t_{i}}[/tex]

Put the value from graph

[tex]a_{m}=\dfrac{140-0}{6}[/tex]

[tex]a_{m}=23.3\ cm/s^2[/tex]

**(III). We need to calculate the acceleration of the cart with high fan speed**

**Using formula of acceleration**

[tex]a_{h}=\dfrac{v_{f}-v_{i}}{t_{f}-t_{i}}[/tex]

Put the value from graph

[tex]a_{h}=\dfrac{160-0}{5}[/tex]

[tex]a_{h}=32\ cm/s^2[/tex]

**Hence, (I). The acceleration of the cart with low fan speed is 18 cm/s²**

**(II). The acceleration of the cart with medium fan speed is 23.3 cm/s²**

**(III). The acceleration of the cart with high fan speed is 32 cm/s²**

**Answer:**

18.0, 24.0, 32.0

**Explanation:**

just did it

Martin Luther King, Jr., was awarded the Noble Peace Prize * Yes No

### Answers

martin luther jr was awarded the nobel peace prize

**Answer**

**Explanation:**

duh he was fighting for peace half of his life

Sarah throws a ball directly upward at the edge of a cliff with a starting velocity of 3.0 m/s

It lands on the ground with a final speed of 6.0 m/s

How long is the ball in the air?

Round the answer to two significant digits

### Answers

Answer:

The correct answer is t = 0.92s

Explanation:

Initial velocity v0 = 3.0 m/s

Displacement Δy = ?

Acceleration a = -9.8m/s2

Final velocity v = -6.0m/s

Time t=? Target unknown

We can use the kinematic formula missing Δy to solve for the target unknown t:

V=v0+at

We can rearrange the equation to solve to t:

V-v0=at

t= v-v0/a

Substituting the known value into the kinematic formula gives:

t= (-6.0m/s)-(3.0m/s)

————————————

-9.8m/s2

= -9m/s

—————-

-9.8m/s2

=0.92s

Sarah throws a ball directly upward at the edge of a cliff with a starting velocity of 3.0 m/s. It lands on the ground with a final speed of 6.0 m/s.

How long is the ball in the air?

**Answer: 0.92**

A 0,34-kg volleyball is flying west at 1,98 m/s when it strikes a stationary 0,60-kg basketball dead centre. The volleyball rebounds east at 0,79 m/s. What will be the velocity of the basketball immediately after impact? Choose the east direction as positive.

### Answers

**Explanation:**

use the law of conservation of momentum

M1U1+M2U2=M1V1+M2V2

m-mass

u-initial velocity

v-final velocity

1-volleyball

2-basket ball dead center

so using the above formula

0.34×1.98+0.64×0=0.34×0.79+0.64×V2

to get

0.6732+0 = 0.2686+0.64V2

0.4046=0.64V2

divide both sides by 0.64 to get V2 which is the final velocity of basketball

0.6322m/s=V2

The **final velocity **of the **basketball** after the impact is **1.643 m/s west**.

The given parameters;

*mass of the volleyball, m = 0.34 kg**initial velocity of the volleyball, u₁ = 1.98 m/s**mass of the stationary basketball, m₂ = 0.6 kg**final velocity of the volleyball, v₁ = 0.79 m/s*

The **final velocity** of the **basketball** after the impact is calculated by applying the principle of **conservation** of** linear momentum;**

m₁u₁ + m₂u₂ = m₁v₁ + m₂v₂

0.34(-1.98) + 0.6(0) = 0.79(0.34) + 0.6(v₂)

-0.673 = 0.316 + 0.6v₂

-0.989 = 0.6v₂

[tex]v_2 = \frac{- 0.989}{0.6} \\\\v_2 = -1.643 \ m/s\\\\v_2 = 1.643 \ m/s \ west[/tex]

Thus, the **final velocity **of the **basketball** after the impact is **1.643 m/s west**.

Learn more here:https://brainly.com/question/24424291

After you let go of a bowling ball, is there a force pushing it so that it keeps moving

forward? Explain.

### Answers

**Explanation:**

No, the ball keeps moving forward due its momentum.

A net force causes an object to accelerate, which means it speeds up, slows down, or changes direction. A bowling ball does not speed up after you let go, so there is no forward force.

The time period of a wave T is the the time taken to produce one complete wave. If the frequency of a wave is 2 Hz, what is it’s time period?

### Answers

**Answer:**

0.5s

**Explanation:**

if the frequency is 2Hz that means it makes 2 complet cycles in one second. The time period for one cycle would be 0.5s

what's the meaning of phisikos

### Answers

A word-forming element meaning "physical, physically; natural," from Latinized form of Greek physikos "natural, physical, pertaining to nature."

A plane takes off at an angle of 30 degrees at a speed of 150 km/h. Determine the horizontal

and vertical components of this velocity vector.

### Answers

**Answer:**

Horizontal Component = 129.9 km/h

Vertical Component = 75 km/h

**Explanation:**

When a vector is resolved on the x-axis and the y-axis, the components so formed are called its rectangular components. The component along y-axis is called the vertical component and the component along x-axis is called horizontal component. These components can be given by following formulae:

**Horizontal Component = v Cos θ**

**Vertical Component = v Sin θ**

where,

v = velocity = 150 km/h

θ = angle = 30°

Therefore,

**Horizontal Component = (150 km/h)(Cos 30°)**

**Horizontal Component = 129.9 km/h**

**Vertical Component = (150 km/h)(Sin 30°)**

**Vertical Component = 75 km/h**

A kettle of water is heated on a stove. What will happen to the molecules of the water in the kettle as the kettle continues to be heated by the flame?

### Answers

**Answer:**

The molecules will take the heat energy and convert it to mechanical energy and they get "excited" and eventually their bonds will break and they will turn into water vapor.