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3 years ago

The main difference between speed and velocity involves

2 answers:

8 0

A. Direction

Speed is just distance divided by time, but velocity is displacement divided by time and displacement has direction. Speed will always be positive, but velocity can be either positive or negative.

torisob [31]3 years ago

3 0

The Correct answer to this question for Penn Foster Students is: Direction

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Consider a uniform solid sphere of radius R and mass M rolling without slipping. Which form of its kinetic energy is larger, tra

castortr0y [4]

Answer:

A. Its translational kinetic energy is larger than its rotational kinetic energy.

Explanation:

Given that

Radius = R

Mass = M

We know that mass moment of inertia for the solid sphere

$I=\dfrac{2}{5}MR^2$

Lets take angular speed =ω

Linear speed =V

Condition for pure rolling , V= ω R

Rotation energy ,RE

$RE=\dfrac{1}{2}I\omega^2$

$RE=\dfrac{1}{2}\times \dfrac{2}{5}MR^2\times \omega^2$

$RE=\dfrac{1}{5}\times MR^2\times \omega^2$

$RE=\dfrac{1}{5}\times MV^2$

RE= 0.2 MV²

The transnational kinetic energy TE

$TE=\dfrac{1}{2}MV^2$

TE= 0.5 MV²

From above we can say that transnational energy is more than rotational energy.

Therefore the answer is A.

3 0

2 years ago

Driving on asphalt roads entails very little rolling resistance, so most of the energy of the engine goes to overcoming air resi

nirvana33 [79]

Answer:

a) $F = 882.63\,N$ , b) $\dot W= 4413.15\,W$ , c) $\eta = 15.216\,\%$ .

Explanation:

a) Let assume that car travel on a horizontal surface. The equations of equilibrium of the car are:

$\Sigma F_{x} = F - \mu_{r}\cdot N = 0$

$\Sigma F_{y} = N - m\cdot g = 0$

After some algebraic handling, the following expression for the propulsion force is constructed:

$F = \mu_{r}\cdot m \cdot g$

$F = (0.06)\cdot (1500\,kg)\cdot (9.807\,\frac{m}{s^{2}} )$

$F = 882.63\,N$

b) The power require to move the car at a speed of 5 meters per second is:

$\dot W = F\cdot v$

$\dot W = (882.63\,N)\cdot (5\,\frac{m}{s} )$

$\dot W= 4413.15\,W$

c) The efficiency of the car is:

$\eta = \frac{(882.63\,N)\cdot (15\,mi)\cdot (\frac{1609\,m}{1\,mi} )}{(1.4\times 10^{8}\,J)} \times 100\,\%$

$\eta = 15.216\,\%$

3 0

3 years ago

Both a 3 kg book and 5 kg bowling ball are sitting still on the floor. What is true about the kinetic energy of the objects? Exp

Charra [1.4K]

Answer:

The kinetic energy for both objects is the same.

Explanation:

While in other cases the kinetic energies of two objects that have different masses might be different depending on their velocities, in this case both the 3 kg book and 5 kg bowling ball have the same kinetic energy.

This is because kinetic energy is calculated using the formula: K = 1/2 * m * v^2, where m represents the mass and v represents the velocity of the object.

Since the book and the bowling ball are sitting still on the floor, their velocities are zero. Hence, when we plug in 0 for velocity into the equation for kinetic energy, we will get that the kinetic energy is 0 for the book and the bowling ball.

Hope this helps!

6 0

2 years ago

What is the Force in Newtons exerted by cart with a mass of 0.75 kg and an Acceleration of 6m/s2?

denis-greek [22]

Answer:

Explanation:

The force acting on an object given it's mass and acceleration can be found by using the formula

force = mass × acceleration

From the question we have

force = 0.75 × 6 = 4.5

We have the final answer as

Hope this helps you

6 0

2 years ago

Which sentence uses a verb incorrectly?

Burka [1]

Answer:

The answer is B).

Explanation:

The correct way to write this sentence is: After I woke up this morning, I got me a tall glass of orange juice.

5 0

3 years ago