If the acceleration is constant (negative or positive) the instantaneous acceleration cannot be

Average acceleration: [final velocity - initial velocity ] /Δ time

Instantaneous acceleration = d V / dt =slope of the velocity vs t graph

If acceleration is increasing, the slope of the curve at one moment will be higher than the average acceleration.

If acceleration is decreasing, the slope of the curve at one moment will be lower than the average acceleration.

If acceleration is constant, the acceleration at any moment is the same, then only at constant accelerations, the instantaneuos acceleration is the same than the average acceleration.

Constant zero acceleration is a particular case of constant acceleration, so at constant zero acceleration the instantaneous accelerations is the same than the average acceleration: zero. But, it is not true that only at zero acceleration the instantaneous acceleration is equal than the average acceleration.

That is why the only true option and the answer is the option D. only at constant accelerations.

3 0

4 years ago

The mass of the sun is 1.99x10^30 kg . Jupiter is 7.79x10^8 km away from the sun and the mass of 1.90x10^27 kg

maks197457 [2]

Question is missing:

"What is the gravitational force between the Sun and Jupiter?"

Answer:

$4.16\cdot 10^{23} N$

Explanation:

The gravitational force between two objects is given by

$F=G\frac{m_1m_2}{r^2}$

where

$G=6.67\cdot 10^{-11} m^3 kg^{-1} s^{-2}$ is the gravitational constant

m1, m2 are the masses of the two objects

r is the separation between the objects

In this problem, we have

$m_1 = 1.99\cdot 10^{30} kg$ is the mass of the sun

$m_2 = 1.90\cdot 10^{27} kg$ is the mass of Jupiter

$r=7.79\cdot 10^8 km = 7.79\cdot 10^{11} m$ is their separation

Solving the equation, we find

$F=(6.67\cdot 10^{-11})\frac{(1.99\cdot 10^{30})(1.90\cdot 10^{27})}{(7.79\cdot 10^{11})^2}=4.16\cdot 10^{23} N$

6 0

3 years ago

An object is 10 cm from the mirror, its height is 1 cm and the focal length is 5 cm. What is the distance from the image to the

7nadin3 [17]

The answer to the question is 10

5 0

4 years ago

Read 2 more answers

Which statement best describes the electrochemical gradient for chloride ions in the figure, assuming the chloride concentration

Natasha_Volkova [10]

<h3><u>Answer;</u></h3>

It favors the movement of chloride ions from the inside to the outside of the cell.

<h3><u>Explanation;</u></h3>

Electrochemical gradient refers to a gradient of electrochemical potential, normally for ions that can move across a membrane.
Normally sodium (Na+) and chloride (Cl−) ions are at high concentrations in the extracellular region, and low concentrations in the intracellular regions.
Assuming the chloride ions are equal on both sides of the membrane the electrochemical gradient for chloride ions favors the movement of chloride ions from the inside to the outside of the cell.

4 0

3 years ago