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3 years ago

a car travelling at 50km/h from rest covers a distance of 10km in 40minutes. Calculate the acceleration

Physics

1 answer:

Margarita [4]3 years ago

7 0

Answer:

$9.67\cdot 10^{-3}m/s^2$

Explanation:

We can solve the problem by using the following suvat equation:

$v^2-u^2=2as$

where

v is the final velocity

u is the initial velocity

a is the acceleration

s is the displacement

For the car in this problem:

u = 0 (it starts from rest)

$v=50 km/h \cdot \frac{1000}{3600}=13.9 m/s$ is the final velocity

s = 10 km = 10 000 m is the displacement

Solving for a, we find:

$a=\frac{v^2-u^2}{2s}=\frac{13.9^2}{2(10000)}=9.67\cdot 10^{-3}m/s^2$

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Natasha_Volkova [10]

Answer:

i think it might be D or C

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3 years ago

a man drags a 8.10 kg bag of mulch at a constant speed, applying a 29.5 N at 38°. what is the coefficient of friction?

lesantik [10]

Answer:

The coefficient of friction is 0.38.

Explanation:

The free body diagram is drawn below.

Let $f$ be frictional force acting in the backward direction as shown. Let the coefficient of friction be $\mu$ . Let $N$ be the normal reaction force acting on the bag.

Given:

Mass of the bag is, $m=8.10\textrm{ kg}$

Force acting at $\theta = 38$ ° is $F= 29.5\textrm{ N}$

Acceleration due to gravity is, $g=9.8\textrm{ }m/s^{2}$

The force F can be resolved into its components as $F_{x}=F \cos \theta$ and $F_{y}=F \sin \theta$

Therefore,

$F_{x}=29.5\cos(38)=23.25\textrm{ N}\\F_{y}=29.5\sin(38)=18.16\textrm{ N}$

Now, as there is no acceleration in vertical direction, therefore,

Sum of upward forces = Sum of downward forces

$N+F_{y}=mg\\N=mg-F_{y}=8.10\times 9.8-18.16\\N=79.38-18.16=61.22\textrm{ N}$

Now, as the bag is moving at a constant speed, so acceleration in the horizontal direction is also zero as acceleration is the rate of change of velocity.

Therefore, backward force = forward force.

$f=F_{x}\\f=23.25\textrm{ N}$

Now, frictional force is given as:

$f=\mu N\\\mu = \frac{f}{N}=\frac{23.25}{61.22}=0.38$

Therefore, the coefficient of friction is 0.38.

8 0

3 years ago

g The speed of light in a vacuum is larger for short wavelength electromagnetic waves. larger for high frequency electromagnetic

Orlov [11]

Answer:

A constant value everywhere in the universe.

Explanation:

The speed of light in a vacuum is a constant value. It is not affected by change in frequency or wavelength of the light.

Mathematically the speed of light is given as:

c = λf

where λ = wavelength and f - frequency

The speed of light is the constant of proportionality between frequency and wavelength. In order words, wavelength and frequency are inversely proportional. As the wavelength increases, frequency decreases and vice versa.

While the change in wavelength and frequency of light affect the energy of the light, its speed is a constant value as long as the medium is a vacuum.

The speed of light is also not dependent on the manner with which the light wave is moving.

4 0

2 years ago

The mass of the block in the drawing is 10 kg. The coefficient of static friction between the block and the vertical wall is 0.5

antiseptic1488 [7]

Answer:

The minimum force to start the block moving up the wall = 49 N

Explanation:

Friction: This is the force that tend to oppose the motion of two bodies in contact. The S.I unit of frictional force is Newton (N)

The minimum force required to start the block moving up the wall = Frictional Force.

I.e F = Frictional force.

And, F = μR..........................Equation 1

Where μ = coefficient of static friction, R = Normal reaction.

But R = mg ( on a level surface).................. Equation 2

Where m = mass, g = acceleration due to gravity.

Given: m = 10 kg,

Constant: g = 9.8 m/s²

substituting these values into Equation 2

R = 10 × 9.8

R = 98 N.

Also given: μ = 0.50

Substituting these values into equation 1

F = 98 × 0.5

F = 49 N.

Therefore The minimum force to start the block moving up the wall = 49 N

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2 years ago

Dark matter has been detected by its

Zinaida [17]

Dark matter has been detected by its gravitational pull.

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3 years ago

a car travelling at 50km/h from rest covers a distance of 10km in 40minutes. Calculate the acceleration​

a car travelling at 50km/h from rest covers a distance of 10km in 40minutes. Calculate the acceleration