If we decrease the time it takes for a car to travel over the same distance, this will

Why is accelration negative when velocity is positive.

Sindrei [870]

Answer:

An object which moves in the positive direction has a positive velocity. If the object is slowing down then its acceleration vector is directed in the opposite direction as its motion (in this case, a negative acceleration).

Explanation:

8 0

3 years ago

A 0.450 kg soccer ball has a kinetic energy of 119 J.

Anastaziya [24]

Answer:

V is approximately = 23m/s

Explanation:

Kinetic energy = ½ mv²

Where m= mass = 0.450kg

V= velocity =?

K. E = 119J

Therefore

K. E = ½ mv²

Input values given

119= ½ × 0.450 × v²

Multiply both sides by 2

119 ×2 = 2 × 1/2 × 0.450 × v²

238= 0.450v²

Divide both sides by 0.450

238/0.450 = 0.450v²/0.450

v² = 528.89

Square root both sides

Sq rt v² = sq rt 528.89

V = 22.998m/s

V is approximately = 23m/s

I hope this was helpful, please rate as brainliest

8 0

3 years ago

Wind tends to move from pressure areas. low, high high, high low, low high, low

andrew-mc [135]

Answer:

high, low

Explanation:

Energy always flows from a higher level to a lower level.
It is analogous to the waterfall where waterfalls from a higher level to a lower level.
So in the case of the pressure of the gas, when there are any numbers of molecules in a given volume of space. The gas is said to be at high pressure.
When there are fewer molecules in the given volume. The gas is said to be at lower pressure.
Due to a large number of atoms, the high-pressure gas exerts more force on the container than the force exerted by the low-pressure gas.
If a hose is connected between these two containers, gas rushes from high pressure to the low pressure. Since the force exerted by the high-pressure gas is greater than that of low-pressure gas.

So, the wind tends to move from high-pressure areas to low pressure.

3 0

3 years ago

The barometric pressure at sea level is 30 in of mercury when that on a mountain top is 29 in. If the specific weight of air is

stealth61 [152]

To solve this problem we will apply the concepts related to pressure, depending on the product between the density of the fluid, the gravity and the depth / height at which it is located.

For mercury, density, gravity and height are defined as

$\rho_m = 846lb/ft^3$

$g = 32.17405ft/s^2$

$h_1 = 1in = \frac{1}{12} ft$

For the air the defined properties would be

$\rho_a = 0.0075lb/ft^3$

$g = 32.17405ft/s^2$

$h_2 = ?$

We have for equilibrium that

$\text{Pressure change in Air}=\text{Pressure change in Mercury}$

$\rho_m g h_1 = \rho_a g h_2$

Replacing,

$(846)(32.17405)(\frac{1}{12}) = (0.0075)(32.17405)(h_2)$

Rearranging to find $h_2$

$h_2 = \frac{(846)(32.17405)(\frac{1}{12}) }{(0.0075)(32.17405)}$

$h = 9400ft$

Therefore the elevation of the mountain top is 9400ft

7 0

3 years ago

A loop rests in the plane of a page of textbook while a magnetic field is directed into the page. A clockwise current is induced

Sunny_sXe [5.5K]

Answer:

When the magnetic field is tilted so it is no longer perpendicular to the page.

When the magnetic field gets stronger.

When the size of the loop decreases.

Explanation:

According to the Faraday-Lenz law, the change of the magnetic flux over time causes an induced current, this flux is given by:

$\Phi_B=BScos\theta$

Therefore, there will be a variable magnetic flux, when the magnitude of the magnetic field (B) changes over time, when the area of the loop (S) changes over time and / or when the angle ( $\theta$ ) between the field and the surface vector changes over time.

8 0

3 years ago