An airplane flying at 119 m/s is accelerated uniformly at the rate of 0.5 m/s2 for 10

In moving out of a dormitory at the end of the semester, a student does 1.82 x 104 J of work. In the process, his internal energ

emmainna [20.7K]

Answer:

Explanation:

(a) Work done, W = 1.82 x 10^4 J

(b) internal energy, U = - 4.07 x 10^4 J ( as it decreases)

(c) According to the first law of thermodynamics

Q = W + U

Q = 1.82 x 10^4 - 4.07 x 10^4

Q = - 2.25 x 10^4 J

4 0

3 years ago

During convection of air currents,

pav-90 [236]

During convection of air currents, cool air sinks. <em>(b)</em>

4 0

3 years ago

Read 2 more answers

A frog leaps up from the ground and lands on a step 0.1 m above the ground 2 s later. We want to find the

mash [69]

Answer:

$\Delta x = v_0 t + \frac{1}{2}at^2$

Explanation:

To solve this problem, we can use the following suvat equation:

$\Delta x = v_0 t + \frac{1}{2}at^2$

where

$\Delta x$ is the vertical displacement of the frog

$v_0$ is the initial vertical velocity

t is the time

a is the acceleration

We have chosen this formula because apart from $v_0$ , all the other quantities are known. In fact:

$\Delta x =0.1 m$ is the vertical displacement

t = 2 s is the total time of flight

$a=g=-9.8 m/s^2$ is the acceleration due to gravity (negative because it is downward)

Therefore, solving for $v_0$ , we find the initial velocity of the frog:

$v_0 = \frac{\Delta x-\frac{1}{2}at^2}{t}=\frac{0.1-\frac{1}{2}(-9.8)(2)^2}{2}=9.85 m/s$

4 0

3 years ago

the core of the earth is made of iron.if the core of the earth is about 10300 degrees Fahrenheit,why then is the core melting in

Citrus2011 [14]

melting point iron less than 10300

7 0

3 years ago

In 2 minutes, a ski lift raises four skiers at a constant speed to a height of 123 m. The average mass of each skier is 71 kg. W

serious [3.7K]

Answer:

The average power provided by the tension in the cable pulling the lift is = 714 W

Explanation:

Given data

Mass = 71 kg

Change in height = 123 m

When the lift moves in upward direction then in that case kinetic energy is constant & only potential energy changes.

Change in potential energy Δ PE = m g ( $h_f - h _ i$ )

Δ PE = 71 × 9.81 × 123

Δ PE = 85670.73 J

Time = 2 min = 120 sec

So average power is given by

$P_{avg} = \frac{Change \ in \ potential \ energy}{Time}$

$P_{avg} = \frac{85670.73}{120}$

$P_{avg} = 714 \ W$

Therefore the average power provided by the tension in the cable pulling the lift is = 714 W

7 0

3 years ago