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2 months ago

Guest #6876843

2 months ago

**Answer : The approximate acceleration of the car is, **

**Solution : Given,**

Initial velocity of the car = 0 m/s

Distance covered = 120 meter

Time taken = 6.32 second

**Using second law of motion,**

where,

s = distance covered

u = initial velocity

t = time taken

a = acceleration

Now put all the given values in the above equation, we get

**Therefore, the approximate acceleration of the car is, **

Guest #6876844

2 months ago

Using kinematic equation s=ut + 1/2 at^2(u = initial velocity=0, s=120m, t= 6.32s), 120 = 0(t) + 1/2 a(6.32)^2. a = 120x2/(6.32)^2 = 6m/s^2.

Question

When Nina jumps into the air, the Earth pulls her back down through the force of gravity. What else occurs? Nina’s gravitational force pushes away from the Earth.
Nina exerts a gravitational pull on the Earth, but the Earth does not accelerate at all.
Nina pulls the Earth toward her, but the Earth’s acceleration is too small to notice.
The force of gravity pulling Nina back down to Earth is the only force occurring.

Solution 1

It is A. hope this helps

Solution 2

1) WRONG. Since gravitational force is an attractive force.

2) WRONG. The Earth does accelerate but the acceleration is so small that it's negligible. However it DOES ACCELERATE.

3) CORRECT.

4) WRONG. Mass means gravitational field, so Nina might be small compared to the Earth but it still creates a gravitational field around her. This answer is also wrong because it's breaking Newton's third law of action-reaction. If Earth pulls Nina, then Nina pulls the Earth back with the same force. Yes, with the SAME FORCE, however F=m*a, so the great difference in mass makes Nina's acceleration much bigger than the Earth's one.

2) WRONG. The Earth does accelerate but the acceleration is so small that it's negligible. However it DOES ACCELERATE.

3) CORRECT.

4) WRONG. Mass means gravitational field, so Nina might be small compared to the Earth but it still creates a gravitational field around her. This answer is also wrong because it's breaking Newton's third law of action-reaction. If Earth pulls Nina, then Nina pulls the Earth back with the same force. Yes, with the SAME FORCE, however F=m*a, so the great difference in mass makes Nina's acceleration much bigger than the Earth's one.

Question

The speed of an object determines the amount of inertia?
True or False

Solution 1

The answer to this question is false.

Solution 2

The answer to your question is false.

Question

A plane is traveling with an air velocity of 720 kilometers/hour due east. It experiences a headwind of 16 kilometers/hour. Find the resultant velocity and direction of the plane with respect to the ground.

Solution 1

**Answer:**

The resultant velocity and direction of the plane with respect to the ground is 704 km/h due east.

**Explanation:**

**Given that,**

Air velocity v₁= 720 km/h

Headwind v₂ = 16 km/h

The air velocity due to east is greater then the head wind.

So, the direction of the velocity respect to the ground will be due to east.

The velocity of plane respect to ground

The resultant velocity will be

**Hence, The resultant velocity and direction of the plane with respect to the ground is 704 km/h due east. **

Solution 2

If it is a headwind it means it's travelling against the motion of the plane. This means it's velocity is simply v=720-16=704 km/h due east.

Question

Select all the correct answers. In which situations is work being done?
A. Hannah leans against her locker, but it doesn’t move.
B. Andy’s car rolls down a hill with the engine off.
C. A wind turbine stands still on a sunny, windless day.
D. A balloon expands as it is heated by the Sun.
E. James pedals a stationary exercise cycle that doesn’t move.

Solution 1

E. James pedals a stationary exercise cycle that doesn’t move.

B. Andy’s car rolls down a hill with the engine off.

These Answer's Are Correct For It Show's Work Being Done A Car Moving Is Working, Pedaling A Exercise Machine Is Working Even If It Doesn't Move It Is Meant To Help You Work Out Pedaling Help's There Is No Need For It To Move.

B. Andy’s car rolls down a hill with the engine off.

These Answer's Are Correct For It Show's Work Being Done A Car Moving Is Working, Pedaling A Exercise Machine Is Working Even If It Doesn't Move It Is Meant To Help You Work Out Pedaling Help's There Is No Need For It To Move.

Solution 2

Answer: The statements B and D are correct answers.

Explanation:

**Work is done when the force is applied to an object then there will be displacement by the object.**

In the option A, Hannah leans against her locker, but it doesn’t move. There is no displacement in this case. The work done is said to be zero in this case.

**In the option B, Andy’s car rolls down a hill with the engine off. There is displacement in this case. The work is said to done in this case. At the hill, the car has a maximum potential energy. **

**When it rolls down then the kinetic energy of the car will increase. From the work energy theorem, the change in the kinetic energy is equal to the work done.**

In the option C, A wind turbine stands still on a sunny, windless day. The work done is said to zero in this case.

**In the option, A balloon expands as it is heated by the Sun. There is expansion of the balloon. The work is done in this case as the volume and the pressure will also increase on heating the balloon.**

In the option E, James pedals a stationary exercise cycle that doesn’t move. No work is done in this case.

Therefore, the statements B and D are correct answers.

Question

A sedimentary rock composed of which of the following would weather at a faster rate? Zircon
Quartz
Calcite
Sand

Solution 1

**Answer:**

sand

**Explanation:**

no

Question

Which situation best describes the act of reducing? paying bills online instead of sending paper through the mail
donating gently used clothes and household items
using plastic bags a second time to avoid buying new ones
buying products that can be recycled so they don’t end up in the trash

Solution 1

**Answer:**

paying bills online instead of sending paper through the mail

**Explanation:**

In today's era everyone is aware about the Climate change and wants to contribute towards environment protection. A simple technique is to follow four R's which are: Reduce, Reuse, Recycle and Refuse. The four examples given over here are examples of each R as explained below:

**Reduce: **paying bills online instead of sending paper through the mail as we are reducing the paper use over here.

**Reuse: **donating gently used clothes and household items so that they can be reused. Using plastic bags a second time to avoid buying new ones.

**Recycle & Refuse: **buying products that can be recycled so they don’t end up in the trash

Solution 2

A - i think

paying bills online?

paying bills online?

Question

Which item is made from an alloy?
steel tray
glass plate
credit card
copper wire

Solution 1

I think its steel plate

Solution 2

**Steel Tray**

its steel tray because i got it right

Question

If a car travels 30 mi. north for one-half hour, 50. mi. east for one hour, and 30 mi. south for 30 min., what is the total distance the car traveled?

Solution 1

**Answer:**

110 mi

**Explanation:**

d1 = 30 mi, d2 = 50 mi, d3 = 30 mi

Distance is defined as the length of actual path traveled.

So, total distance, d = d1 + d2 + d3 = 30 + 50 + 30 = 110 mi

Solution 2

50 miles to the east hope it helps

Question

A 45 kg student runs up a flight of stairs that are 3.2 m high in 2 seconds. How much power did the student use during this time? 706 W
288 W
72 W
7.0 W

Solution 1

The **power** used by the **student** is equal to 706.32 W. Therefore, option A is correct.

The **power** can be demonstrated as the rate of doing **work** and can be defined as the **work done** in unit **time**. The SI unit of power can be expressed as joules per second (J/s) or **Watt**.

**Power** can be described as a** time-based parameter** and the rate at which **work** is done on a body. The mathematical formula for **power** can be represented as mentioned below.

Power = Work/ time

P = W/t

Given, the **mass** of the student, m = 45 kg

Consider, the **height** of the stairs, h = 3.2 m

The** work done **by the student, W = mgh,

W = 45 × 9.81 × 3.2

W = 1412.64 J

The **power** used by the student, P = W/t

P = 1412.64/2

P = 706.32 W

Therefore, the **power** did the **student** use during this time is 706.32 W.

Learn more about **power**, here:

#SPJ2

Solution 2

Question

A 6000 kg train car traveling at 2.5 m/s collides with another 6000 kg train car, now they are both moving but with a speed of 1.25 m/s. This is an example of

Solution 1

A 6000 kg train car traveling at 2.5 m/s collides with another 6000 kg train car, now they are both moving but with a speed of 1.25 m/s. This is an example of Conservation of Momentum.You can prove it by (6000kg)(2.5m/s)+(6000kg)(0m/s= (6000+6000kg)(1.25m/s).

Hope this helps :)

If anymore questions let me know.

Hope this helps :)

If anymore questions let me know.

Solution 2

This is an example of inelastic collision because after collision they both move with same velocity.

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