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4 years ago

Physics question i appreciate your help please

Physics

1 answer:

hichkok12 [17]4 years ago

5 0

There are two numbers i.e (c) and (d) with 4 significant figures, since we start counting the first non-zero digit from the left, therefore, A. Has 1 significant figure, B has 5 significant figurea and C,D have 4 significant figures.

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iron ball weight 400 gram inside water when it is completely impressed in water 53 gram water is displaced what will be the weig

Alika [10]

Answer:

453 gm

Explanation:

<u>Immersed </u>objects are buoyed up by force equal to mass of displaced liquid

400 + 53 = 453 gm in air

8 0

2 years ago

A loaded 375 kg toboggan is traveling on smooth horizontal snow at 4.50 m/s when it suddenly comes to a rough region. The region

zmey [24]

Answer:

a) The average friction force exerted on the toboggan is 653.125 newtons, b) The rough region reduced the kinetic energy of the toboggan in 92.889 %, c) The speed of the toboggan is reduced in 73.333 %.

Explanation:

a) Given the existence of non-conservative forces (friction between toboggan and ground), the motion must be modelled by means of the Principle of Energy Conservation and the Work-Energy Theorem, since toboggan decrease its speed (associated with due to the action of friction. Changes in gravitational potential energy can be neglected due to the inclination of the ground. Then:

$K_{1} = K_{2} + W_{f}$

Where:

$K_{1}$ , $K_{2}$ are the initial and final translational kinetic energies of the tobbogan, measured in joules.

$W_{f}$ - Dissipated work due to friction, measured in joules.

By applying definitions of translation kinetic energy and work, the expression described above is now expanded and simplified:

$f\cdot \Delta s = \frac{1}{2}\cdot m \cdot (v_{1}^{2}-v_{2}^{2})$

Where:

$f$ - Friction force, measured in newtons.

$\Delta s$ - Distance travelled by the toboggan in the rough region, measured in meters.

$m$ - Mass of the toboggan, measured in kilograms.

$v_{1}$ , $v_{2}$ - Initial and final speed of the toboggan, measured in meters per second.

The friction force is cleared:

$f = \frac{m\cdot (v_{1}^{2}-v_{2}^{2})}{2\cdot \Delta s}$

If $m = 375\,kg$ , $v_{1} = 4.50\,\frac{m}{s}$ , $v_{2} = 1.20\,\frac{m}{s}$ and $\Delta s = 5.40 \,m$ , then:

$f = \frac{(375\,kg)\cdot \left[\left(4.50\,\frac{m}{s} \right)^{2}-\left(1.20\,\frac{m}{s}\right)^{2}\right]}{2\cdot (5.40\,m)}$

$f = 653.125\,N$

The average friction force exerted on the toboggan is 653.125 newtons.

b) The percentage lost by the kinetic energy of the tobbogan due to friction is given by the following expression, which is expanded and simplified afterwards:

$\% K_{loss} = \frac{K_{1}-K_{2}}{K_{1}}\times 100\,\%$

$\% K_{loss} = \left(1-\frac{K_{2}}{K_{1}} \right)\times 100\,\%$

$\% K_{loss} = \left(1-\frac{\frac{1}{2}\cdot m \cdot v_{2}^{2}}{\frac{1}{2}\cdot m \cdot v_{1}^{2}} \right)\times 100\,\%$

$\% K_{loss} = \left(1-\frac{v_{2}^{2}}{v_{1}^{2}} \right)\times 100\,\%$

$\%K_{loss} = \left[1-\left(\frac{v_{2}}{v_{1}}\right)^{2} \right]\times 100\,\%$

If $v_{1} = 4.50\,\frac{m}{s}$ and $v_{2} = 1.20\,\frac{m}{s}$ , then:

$\%K_{loss} = \left[1-\left(\frac{1.20\,\frac{m}{s} }{4.50\,\frac{m}{s} }\right)^{2} \right]\times 100\,\%$

$\%K_{loss} = 92.889\,\%$

The rough region reduced the kinetic energy of the toboggan in 92.889 %.

c) The percentage lost by the speed of the tobbogan due to friction is given by the following expression:

$\% v_{loss} = \frac{v_{1}-v_{2}}{v_{1}}\times 100\,\%$

$\% v_{loss} = \left(1-\frac{v_{2}}{v_{1}} \right)\times 100\,\%$

If $v_{1} = 4.50\,\frac{m}{s}$ and $v_{2} = 1.20\,\frac{m}{s}$ , then:

$\% v_{loss} = \left(1-\frac{1.20\,\frac{m}{s} }{4.50\,\frac{m}{s} } \right)\times 100\,\%$

$\%v_{loss} = 73.333\,\%$

The speed of the toboggan is reduced in 73.333 %.

5 0

3 years ago

a truck was traveling at 16.6 miles per second and accelerates at a rate of 2.0 meters per second squared how much time is requi

Ivan

A truck was traveling at 16.6 miles per second and accelerates at a rate of 2.0 meters per second squared then time is required for the truck to reach a speed of 25 miles per second is 6759 s.

Explanation:

Velocity is defined as the rate of change in displacement while acceleration is defined as the rate of change of velocity. Acceleration may be positive or negative. Acceleration is positive when the velocity of the object is increases and it is negative when velocity of the object is decreases. Negative acceleration is also called deceleration.

Mathematically

a = $\frac{(v_{f} - v_{i})}{t}$

Where a is the acceleration of the object, $v_{f}$ is the final velocity of the object and $v_{i}$ is the initial velocity of the object. t is equal to time taken.

Given data:

$v_{f}$ = 25 miles/s

$v_{i}$ = 16.6 miles/s

a = 2.0 m/s²

t = ?

As velocities and acceleration given in different units, So we need to convert to obtain same units. Here we convert unit of acceleration from m/s² to miles/s².

1 m/s² = 0.000621371192 miles/s²

2 m/s² = 0.00124274238 miles/s²

So,

a = 0.00124274238 miles/s²

Apply formula

a = $\frac{v_{f} - v_{i}}{t}$

t = $\frac{(v_{f} - v_{i})}{a}$

t = $\frac{(25 - 16.6)}{0.00124274238}$

t = 6759 s

Learn more about velocity and acceleration from

brainly.com/question/1192983

#learnwithBrainly

3 0

3 years ago

Will convection always work faster and more efficiently than conduction?

Stells [14]

Answer:

Yes convection will always work faster and more efficiently.

Explanation:

When a gas or a liquid is heated, hot areas of the material flow and mix with the cool areas. ... Convection transfers heat over a distance faster than conduction. But ultimately conduction must transfer the heat from the gas to the other object, though molecular contact.

5 0

3 years ago

The atomic number of an element is 75. is this element diamagnetic or paramagnetic?

tatyana61 [14]

I think it is diamagnetic don't quught me thoi

6 0

3 years ago