Calculating Potential Energy

To what temperature will a 79.0 g piece of glass raise if it absorbs 9457 calories of heat and its specific heat capacity is 0.5

ruslelena [56]

Answer:

T_final = 279.4 [°C]

Explanation:

In order to solve this problem, we must use the following equation of thermal energy.

$Q=m*C_{p}*(T_{f}-T_{i})$

where:

Q = heat = 9457 [cal]

m = mass = 79 [g] = 0.079 [kg]

Cp = specific heat = 0.5 [cal/g*°C]

T_initial = initial temperature = 40 [°C]

T_final = final temperature [°C]

$9457 = 79*0.5*(T_{f}-40)\\239.41=T_{f}-40\\\\T_{f}=279.4[C]$

8 0

3 years ago

You are 2.4 from a plane mirror, and you would like to take a picture of yourself in the mirror. You need to manually adjust the

Wittaler [7]

Answer:

option (D)

Explanation:

your distance from the plane mirror = 2.4 m

According to the property of the plane mirror, the distance between the object and the mirror is equal to the distance between the image and the mirror.

So, the distance between you and your image is two times the distance between you and mirror.

the distance between you and your image = 2 x 2.4 = 4.8 m

5 0

3 years ago

A bowling ball is launched off the top of a 240-foot tall building. The height of the bowling ball above the ground t seconds af

natima [27]

Answer:

When the ball hits the ground, its velocity is -128 ft/s.

Explanation:

Hi there!

First, let's find the time it takes the ball to reach the ground (the value of t for which s(t) = 0):

s(t) = -16t² + 32t + 240

0 = -16t² + 32t + 240

Solving the quadratic equation with the quadratic formula:

t = 5.0 s (the other solution of the equation is rejected because it is negative).

Now, we have to find the velocity of the ball at t = 5.0 s.

The velocity of the ball is the change of height over time (the derivative of s(t)):

v = ds/dt = s'(t) = -32t + 32

at t = 5.0 s:

s'(5.0) = -32(5.0) + 32 = -128 ft/s

When the ball hits the ground, its velocity is -128 ft/s.

4 0

3 years ago

What is the centripetal acceleration of the earth as it travels around the sun when Earth has an orbital radius of 1.5 x 10^11 m

masya89 [10]

Answer: $0.0058 m/s^{2}$

Explanation:

Centripetal acceleration $a_{C}$ is calculated by the following equation:

$a_{C}=\frac{V^{2}}{r}$

Where:

$V=29.7 \frac{km}{h} \frac{1000 m}{1 km}=29700 m/s$ is the Earth's orbital speed

$r=1.5(10)^{11} m$ is the orbital radius

$a_{C}=\frac{(29700 m/s)^{2}}{1.5(10)^{11} m}$

$a_{C}=0.0058 m/s^{2}$

4 0

3 years ago

A child pulls on a wagon with a force of 75 N. If the wagon moves a total of 42 m in 3.1 min, what is the average power delivere

exis [7]

Answer:

16.96 W

Explanation:

Power: This can be defined as the rate at which work is done by an object. The S.I unit of power is Watt(W).

From the question,

P = (F×d)/t....................... Equation 1

Where P = power, F = force, d = distance, t = time.

Given: F = 75 N, d = 42 m, t = 3.1 min = 3.1×60 = 186 s

Substitute these values into equation 1

P = (75×42)/186

P = 16.94 W

Hence the average power delivered by the child = 16.96 W

4 0

3 years ago