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1 year ago

A train slows from 60m/s to 20m/s in 50s

Physics

2 answers:

Dovator [93]1 year ago

7 0

Answer:

a = -4/5 m/s^2

Explanation:

Acceleration = change in velocity / time

change in velocity = final velocity - initial velocity

a = (20 m/s - 60 m/s) / 50 s

a = -40 m/s / 50 s

a = -4/5 m/s^2

hope this helps! <3

Alexeev081 [22]1 year ago

4 0

Answer:

Explanation:

It is going from 60 to 20 m/s so ACCELERATION is negative

acceleration = change in velocity / time

= -40 m/s / 50 s = <u>- 4/5 m/s^2 </u>

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A ball is thrown with a velocity of 35 meters per second at an angle of 30° above the horizontal. which quantity has a magnitude

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The quantity that has a magnitude of zero when the ball is at the highest point in its trajectory is the vertical velocity.

In fact, the motion of the ball consists of two separate motions:
- the horizontal motion, on the x-axis, which is a uniform motion with constant velocity $v_x=v_0 cos 30^{\circ}$ , where $v_0=35 m/s$
- the vertical motion, on the y-axis, which is a uniformly accelerated motion with constant acceleration $g=9.81 m/s^2$ directed downwards, and with initial velocity $v_y=v_= sin 30^{\circ}$ . Due to the presence of the acceleration g on the vertical direction (pointing in the opposite direction of the initial vertical velocity), the vertical velocity of the ball decreases as it goes higher, up to a point where it becomes zero and it reverses its direction: when the vertical velocity becomes zero, the ball has reached its maximum height.

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2 years ago

The temperature of a sample of silver increased by 24.0 °C when 269 J of heat was applied. What is the mass of the sample?

statuscvo [17]

Answer:

Mass of the silver will be equal to 46.70 gram

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We have given heat required to raise the temperature of silver by 24°C is 269 J , so $\Delta T=24^{\circ}C$

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We have to find the mass of silver

We know that heat required is given by

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3 years ago

a jet plane traveling 1890 km/h pulls out of a dive by moving in an arc of radius 5.20km. what is planes acceleration in g's

Andrew [12]

Answer:

$53 m/s^2$

Explanation:

Unit conversions:

1890 km/h = 1890 km/h * 1000m/km * 1/3600 h/s = 525 m/s

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Assume that the jets is traveling in perfect circular motion, we can calculate the centripetal acceleration of the motion:

$a = \frac{v^2}{r}$

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3 years ago

What is the kinetic energy of an object moving 40m/s with a mass of 20kg?

Svet_ta [14]

KE = (1/2) (mass) (speed)²

KE = (1/2) (20 kg) (40 m/s)²

KE = (1/2) (20 kg) (1,600 m²/s²)

KE = (10 kg) (1,600 m²/s²)

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3 years ago

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dangina [55]

Answer:

A volume of a cubic meter of water from the surface of the lake has been compressed in 0.004 cubic meters.

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