Select the type of volcanoes that frequently erupt violently?

A 1400 kg car driving at 25 m/s slams on its brakes. The coefficient of kinetic friction between the tires and the road is 0.7.

tamaranim1 [39]

The acceleration of the car is 6.86 m/s² and the time taken for the car to stop is 3.64 s.

The given parameters;

mass of the car, m = 1400 kg
Initial velocity of the car, u = 25 m/s
coefficient of kinetic friction, μ = 0.7

The acceleration of the car is calculated as follows;

a = μg

a = 0.7 x 9.8

a = 6.86 m/s²

The time taken for the car to stop is calculated by using Newton's second law of motion;

F = ma

$F = \frac{mv}{t} \\\\ma = \frac{mv}{t}\\\\a = \frac{v}{t} \\\\t = \frac{v}{a} \\\\t = \frac{25}{6.86} \\\\t = 3.64 \ s$

Thus, the acceleration of the car is 6.86 m/s² and the time taken for the car to stop is 3.64 s.

Learn more here:brainly.com/question/19887955

5 0

3 years ago

Calculate the voltage (in volts) of a solar cell that generates a current of 139 milliamps and has a resistance of 6 ohms.

valkas [14]

Answer:

834 milli-volts

Explanation:

Data provided in the question:

Current = 139 milliamps = 139 × 10⁻³ A

resistance = 6 ohms

Now,

The relation between the current , resistance and voltage is given as:

Voltage = Current × Resistance

on substituting the respective values, we get

Voltage = 139 × 10⁻³ × 6

or

Voltage = 834 milli-volts

8 0

4 years ago

Read 2 more answers

What is the speed of a 16 cm wave with a period of 8 seconds?

sp2606 [1]

The speed of a 16cm wave with a period of 8 seconds is 2cm/s

<h3>How to determine the speed</h3>

Using the formula;

Speed = distance ÷ time

Distance = 16cm

time = 8 seconds

Substitute into the formula

Speed = 16 ÷ 8

Speed = 2 cm/s

Therefore, the speed of a 16cm wave with a period of 8 seconds is 2cm/s

Learn more about speed here:

brainly.com/question/4931057

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3 0

2 years ago

How many photons will be required to raise the temperature of 1.8 g of water by 2.5 k ?'?

tatyana61 [14]

Missing part in the text of the problem:
"<span>Water is exposed to infrared radiation of wavelength 3.0×10^−6 m"</span>

First we can calculate the amount of energy needed to raise the temperature of the water, which is given by
$Q=m C_s \Delta T$
where
m=1.8 g is the mass of the water
$C_s = 4.18 J/(g K)$ is the specific heat capacity of the water
$\Delta T=2.5 K$ is the increase in temperature.

Substituting the data, we find
$Q=(1.8 g)(4.18 J/(gK))(2.5 K)=18.8 J=E$

We know that each photon carries an energy of
$E_1 = hf$
where h is the Planck constant and f the frequency of the photon. Using the wavelength, we can find the photon frequency:
$\lambda = \frac{c}{f}= \frac{3 \cdot 10^8 m/s}{3 \cdot 10^{-6} m}=1 \cdot 10^{14}Hz$

So, the energy of a single photon of this frequency is
$E_1 = hf =(6.6 \cdot 10^{-34} J)(1 \cdot 10^{14} Hz)=6.6 \cdot 10^{-20} J$

and the number of photons needed is the total energy needed divided by the energy of a single photon:
$N= \frac{E}{E_1}= \frac{18.8 J}{6.6 \cdot 10^{-20} J} =2.84 \cdot 10^{20} photons$

4 0

3 years ago

Why do people walks bare feel pain

matrenka [14]

Answer:

As we age the fat pad underneath the bones at the front of our feet (metatarsal heads) and under the heel bone become thinner or “migrate” away from where they are most needed

8 0

3 years ago