after swimming away from captain terror randy enters a 16 yard downhill couch race. how many feet is the race

Can a average velocity be zero.Why?

marishachu [46]

Answer:

Yes

Explanation:

Average velocity is the ratio of total displacement and time taken for that displacement:

$average \space\ velocity = \frac{displacement}{time}$

This means if displacement is zero, then average velocity will also be zero.

Displacement is zero when an object moves some distance in one direction, and then moves the same distance but in the opposite direction.

∴ As it is possible for displacement to be zero, it is also possible for average velocity to be zero.

4 0

2 years ago

4 of

Maksim231197 [3]

Answer:

all of the above????

Explanation:

my teacher told me.

8 0

3 years ago

When 597 J of heat are added to a gas, it expands. Its internal energy increases by 318 J. How much work does the gas do? (Unit=

damaskus [11]

The magnitude of work done by the gas is 279 J and the sign is negative so W = -279 J as work is done by the system.

Explanation:

According to first law of thermodynamics, the change in internal energy of the system is equal to the sum of the heat energy added or released from the system with the work done on or by the system. If the heat energy is added to the system to perform a certain work, then the heat energy is taken as positive, while it will be negative when the heat energy is released from the system.

Similarly, in this case, the heat energy of 597 J is added to the system. So the heat energy will be positive, while the gas expansion occurs means work is done by the system.

ΔU = Q+W

Since ΔU is the change in internal energy which is given as 318 J and the heat energy added to the system is Q = 597 J.

Then the work done by the gas = ΔU - Q = 318 J - 597 J = - 279 J.

As the work is done by the system, so it will be denoted in negative sign and the magnitude of work done by the gas is 279 J.

7 0

3 years ago

After a fall, a 90 kg rock climber finds himself dangling from the end of a rope that had been 16 m long and 7.8 mm in diameter

Nesterboy [21]

Explanation:

Given that,

Mass of the rock climber, m = 90 kg

Original length of the rock, L = 16 m

Diameter of the rope, d = 7.8 mm

Stretched length of the rope, $\Delta L=3.1\ cm$

(a) The change in length per unit original length is called strain. So,

$\text{strain}=\dfrac{\Delta L}{L}\\\\\text{strain}=\dfrac{3.1\times 10^{-2}}{16}\\\\\text{strain}=0.00193$

(b) The force acting per unit area is called stress.

$\text{stress}=\dfrac{mg}{A}\\\\\text{stress}=\dfrac{90\times 10}{\pi (3.9\times 10^{-3})^2}\\\\\text{stress}=1.88\times 10^7\ Pa$

(c) The ratio of stress to the strain is called Young's modulus. So,

$Y=\dfrac{\text{stress}}{\text{strain}}\\\\Y=\dfrac{1.88\times 10^7}{0.00193}\\\\Y=9.74\times 10^9\ N/m^2$

Hence, this is the required solution.

8 0

3 years ago

What is the longest wavelength of light that will emit electrons from a metal whose work function is?

alexdok [17]

Best Answer: hf = work function + KE
However if you are looking at the max wavelength (or threshold frequency) then there will only be just enough energy for the photoelectrons to be liberated, hence their KE will be 0.
So hf = work function
convert eV to joules, 2.4 x (1.6 x 10^-19) = 3.84 x 10^-19
therefore, hf = 3.84 x 10^-19
f = 3.84 x 10^-19 / planck's constant which is 6.63 x 10^-34
f = 5.79 x 10^14 Hz
c = frequency x wavelength,
wavelength = speed of light/frequency
= (3x10^8)/(5.79x10^14)
=5.18 x 10^-7 metres

6 0

3 years ago