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Naily [24]
3 years ago
15

A child pushes a toy car down a hill. The child has a mass of 20 kg. The car has a mass of 1.6 kg and a speed of 7.4 m/s2. When

the car has a gravitational potential energy of 30 J, what is the mechanical energy of the car?
Physics
1 answer:
Andrew [12]3 years ago
5 0

Answer:

The answer is 73.8 J

Explanation:

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Consider two wheels with fixed hubs. The hub cannot move, but the wheel can rotate about it. The hubs are fixed to a stationary
kykrilka [37]

Answer:

Magnitude of force on wheel B is 4 N

Explanation:

Given that

I=mr^2

For wheel A

m= 1 kg

d= 1 m,r= 0.5 m

F=1 N

We know that

T= F x r

T=1 x 0.5 N.m

T= 0.5 N.m

T= I α

Where I is the moment of inertia and α is the angular acceleration

I_A=1 \times 0.5^2\ kg.m^2

I_A=0.25\ kg.m^2

T= I α

0.5= 0.25 α

\alpha = 2\ rad/s^2

For Wheel B

m= 1 kg

d= 2 m,r=1 m

I_B=1 \times 1^2\ kg.m^2

I_B=1 \ kg.m^2

Given that angular acceleration is same for both the wheel

\alpha = 2\ rad/s^2

T= I α

T= 1 x 2

T= 2 N.m

Lets force on wheel is F then

T = F x r

2 = F x 1

So F= 2 N

Magnitude of force on wheel B is 2 N

3 0
3 years ago
Positive electric charge Q is distributed uniformly throughout the volume of an insulating sphere with radius R.From the express
AlladinOne [14]

Answer:

Vb = k Q / r        r <R

Vb = k q / R³ (R² - r²)    r >R

Explanation:

The electic potential is defined by

             ΔV = - ∫ E .ds

We calculate the potential in the line of the electric pipe, therefore the scalar product reduces the algebraic product

             VB - VA = - ∫ E dr

Let's substitute every equation they give us and we find out

r> R

           Va = - ∫ (k Q / r²) dr

           -Va = - k Q (- 1 / r)

We evaluate with it Va = 0 for r = infinity

          Vb = k Q / r        r <R

         

We perform the calculation of the power with the expression of the electric field that they give us

           Vb = - int (kQ / R3 r) dr

  We integrate and evaluate from the starting point r = R to the final point r <R

         Vb = ∫kq / R³ r dr

         Vb = k q / R³ (R² - r²)

This is the electric field in the whole space, the places of interest are r = 0, r = R and r = infinity

8 0
4 years ago
 Acid precipitation is caused by a mix of 
saveliy_v [14]
C. sulfur dioxide, carbon dioxide, and nitrogen oxides

These three chemical compounds play a role in the chemistry of acid rain or acid precipitation. These compounds are then in the process as they evaporate are converted into acids, mainly, nitric acid and sulfuric acid. These toxic gases that composes acid precipitation is actually caused by industries, factories or plants that utilizes such chemicals and then uses a humongous amount which then is released in during the process of certain products or manufactured objects.



4 0
3 years ago
Why is scalar quantity negative charges is not possible​
umka2103 [35]

Answer:

Scalar quantity can never be Negative. Because scalar has only magnitude not direction. And magnitude can't be negative.

Explanation:

4 0
3 years ago
Read 2 more answers
900n pushes a wedge 0.10 m into a log, if the work done on the log is 50j what is the efficiency of the wedge
mariarad [96]

Answer:

100

Explanation:

mark me brainliest

7 0
3 years ago
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