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guapka [62]
3 years ago
9

A motorist wishes to travel 40 kilometers at an average speed of 40 km/h. During the first 20 kilometers, an average speed of 40

km/h is maintained. During the next 10 kilometers. however, the motorist averages only 20 km/h. To drive the remaining 10 kilometers and average 40 km/h, the motorist must drive
a) 60 km/h. b) 80 km/h. c) 90 km/h. d) faster than the speed of light​
Physics
1 answer:
allochka39001 [22]3 years ago
4 0

poste en français s’il vous plaît

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A hot iron ball of mass 200 g is cooled to a temperature of 22°C from 100°C. How much heat was
Nookie1986 [14]

Answer:

Q= -6900 J

Explanation:

use the formula Q=mC(T_2 - T_1) and sub in givens

Q=mC(T_2 - T_1)

Q= (200 g)(0.444 J/g°C)(22-100)

Q= -6900 J

The negative sign means heat is lost, which agrees with the decrease in temperature

6 0
3 years ago
The displacement of a 500 g mass, undergoing simple harmonic motion, is defined by the function :
Delicious77 [7]

The maximum kinetic energy, maximum potential energy and the maximum mechanical energy are equal to 7.56J.

<h3>What is simple harmonic motion?</h3>

Simple harmonic motion, in physics, repetitive movement back and forth through an equilibrium, or central, position, so that the maximum displacement on one side of this position is equal to the maximum displacement on the other side.

Simple Harmonic Motion

The given equation of the simple harmonic motion is

x=3.5 sin (\frac{\pi }{2t} + \frac{5\pi }{4} )

Data;

ω = π/2

k = 1.254N/m

Solving this

\frac{dx}{dt} = -3.5 X \frac{\pi }{2} cos (\frac{x\pi t}{2}+\frac{5\pi }{4}  )

Let's calculate the maximum velocity.

V_{m} =\frac{3.5\pi }{2}

This is only possible when cos θ = -1

The maximum kinetic energy is

K_m =\frac{1}{2} mv^2 = \frac{1}{2} X \frac{500}{1000} X \frac{7^2\pi ^2}^{4} ^2

w^2 = \frac{k}{m} \\k = w^2m\\k = \frac{\pi ^2}{4} X \frac{500}{1000} \\k =1.254 N/m

Using the value of spring constant, we can find the maximum potential energy.

P.E =\frac{1}{2} k x^2\\P.E =\frac{1}{2} X 1.234 X 3.5^2 \\P.E = 7.56 J

The maximum potential energy is 7.56J

The maximum mechanical energy is equal to the sum of maximum potential energy and the maximum kinetic energy.

ME = K.E + P.E

ME = 7.56J

From the calculations above, the maximum kinetic energy, maximum potential energy and the maximum mechanical energy are equal to 7.56J.

Learn more on simple harmonic motion here;

brainly.com/question/15556430

#SPJ1

8 0
2 years ago
Which of the following activities could lead to injuries?
Ipatiy [6.2K]

Answer:

Fighting

Explanation:

Fighting with someone like punch for punch can make the person bleed which an injury to the guy who you fought with and you can be arrested if the parents file a complain at the police station

6 0
3 years ago
Read 2 more answers
2 ways in which a weather satellite can orbit the earth
avanturin [10]

Answer:

The two most common types of orbit are "geostationary" and "polar."

6 0
2 years ago
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to start an avalanche on a mountain slope, an artillery shell is fired with an initial velocity of 290 m/s at 53.0° above the ho
kap26 [50]
So this is easy to calculate when you split the velocity into x and y components. The x component is going to equal cos(53) * 290 and the y component is going to equal sin(53)*290.

The x location therefore is 290*cos(53)*35 = 6108.4m

The y location needs to factor in the downwards acceleration of gravity too, which is 9.81m/s^2. We need the equation dist. = V initial*time + 0.5*acceleration*time^2.

This gives us d=290*sin(53)*35 + (0.5*-9.81*35^2)=2097.5m

So your (x,y) coordinates equals (6108.4, 2097.5)
5 0
3 years ago
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