Use Kirchoff first law and second law to derise the expression for the total resistancs

A shopper pushes a grocery cart 20.0 m at constant speed on level ground, against a 35.0 N frictional force. He pushes in a dire

svp [43]

Answer:

(A). The work done on the cart by the friction is -700 J.

(B). The work done on the cart by the gravitational force is 0 J.

(C). The work done on the cart by the shopper is 700 J.

(D). The force the shopper exerts 38.61 N.

(E). The total work done on the cart is zero.

Explanation:

Given that,

Distance = 20.0 m

Frictional force = 35.0 N

Angle = 25.0°

(A). We need to calculate the work done on the cart by the friction

Using formula of work done

$W_{fr} = -F\cdot d$

Where, F = force

d = distance

Put the value into the formula

$W_{fr}=-35.0\times20$

$W_{fr}=−700\ J$

(B). The work done by the gravity is perpendicular to the direction of the motion

We need to calculate the work done on the cart by the gravitational force

Using formula of work done

$W=fd\cos\theta$

Put the value into the formula

$W=35.0\times20\cos90$

$W=0\ J$

(C). We need to calculate the work done on the cart by the shopper

Using formula of work done

$W_{sh}=W_{net}-W_{fr}$

Put the value into the formula

$W_{sh}=0-(-700)$

$W_{sh}=700\ J$

(D). We need to calculate the force the shopper exerts

Using formula of force

$F_{sh}=\dfrac{W_{fr}}{d\cos\theta}$

Put the value into the formula

$F_{sh}=\dfrac{700}{20\cos25}$

$F_{sh}=38.61\ N$

(E). We need to calculate the total work done on the cart

Using formula of work done

$W_{cart}=W_{fr}+W_{sh}$

Put the value into the formula

$W_{cart}=700-(-700)$

$W_{cart}=0\ J$

Hence, (A). The work done on the cart by the friction is -700 J.

(B). The work done on the cart by the gravitational force is 0 J.

(C). The work done on the cart by the shopper is 700 J.

(D). The force the shopper exerts 38.61 N.

(E). The total work done on the cart is zero.

6 0

3 years ago

Triangulation is the preferred method of calculation for all astronomical distances.

yan [13]

<span>
if it was possible to triangulate all objects it would give the most accurate answer. So yes, it is the prefered method. However as this is not the case other methods are used, less accurate but more practical</span>

8 0

3 years ago

Read 2 more answers

The moon completes one orbit of earth every 27.3 earth days that is its

marishachu [46]

Could be c because it matches the question

7 0

3 years ago

Read 2 more answers

The Nardo ring is a circular test track for cars. It has a circumference of 12.5 km. Cars travel around the track at a constant

KIM [24]

Answer: 50 km, 0, 27.78 m/s

Explanation:

Given

Circumference of the track is $12.5\ km$

Speed of car is $100\ km/h$

Car drives for $30\ \text{minute}\ or\ 0.5\ hr$

(a)Distance traveled is

$\Rightarrow D=100\times 0.5\\\Rightarrow D=50\ km$

(b)displacement of the car

It can be observed that 12.5 is a multiple of 50, that is, 50 km can be interpreted as 4 complete rounds of the track.

Therefore, the displacement of the car is zero.

(c)To convert kmph to m/s, multiply the entity by $\frac{5}{18}$

$\Rightarrow 100\times \dfrac{5}{18}\\\\\Rightarrow 27.78\ m/s$

5 0

3 years ago

A soccer ball of mass 0.4 kg is moving horizontally with a speed of 20 m/s when it is kicked by a player. The kicking force is s

frutty [35]

Answer:

Explanation:

The ball was moving with velocity of 20 m /s earlier in horizontal direction . Due to kicking, additional V velocity was added to it at 40° because he kicked it at this angle but the ball travelled in the direction of resultant which was making an angle of 30° with the horizontal .

From the relation of inclination of resultant

Tan θ = V sinα / (u + V cosα) where α is angle between u and V , θ is inclination of resultant

Tan30 = $\frac{Vsin40}{20+ Vcos40}$

$\frac{1}{\sqrt{3 } } =\frac{V\times .64}{20+ V\times.766}$

20 + .766 V = 1.11 V

20 = .344 V

V = 58 m /s

To know the force , we shall apply concept of impulse

F x t = mv , F is force for time t creating a change of momentum mv

F x .1 = .4 x 58

F = 232 N

6 0

3 years ago

Use Kirchoff first law and second law to derise the expression for the total resistancs​

Use Kirchoff first law and second law to derise the expression for the total resistancs