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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:

- 4/5 m/s^2

Explanation:

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

acceleration = change in velocity / time

= -40 m/s / 50 s = - 4/5 m/s^2

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A student wants to determine the effect of mass on kinetic energy. She will drop two balls of the same size into a pool of water

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Answer:

She should drop two balls with different masses from the same height

Explanation:

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2 years ago

A block of mass 0.500 kg is pushed against a horizontal spring of negligible mass until the spring is compressed a distance x (F

Marrrta [24]

Answer:

Part a)

$x = 0.4 m$

Part b)

$v_i = 11.7 m/s$

Part c)

Speed is more than the required speed so it will reach the top

Explanation:

Part a)

As we know that there is no frictional force while block is moving on horizontal plane

so we can use energy conservation on the block

$\frac{1}{2}mv^2 = \frac{1}{2}kx^2$

$\frac{1}{2}0.500(12^2) = \frac{1}{2}(450)x^2$

$x = 0.4 m$

Part b)

If the track has average frictional force of 7 N then work done by friction while block slides up is given as

$W_f = -7( \pi R)$

$W_f = -7(\pi \times 1.00)$

$W_f = -22 J$

work done against gravity is given as

$W_g = - mg(2R)$

$W_g = -(0.500)(9.8)(2\times 1)$

$W_g = -9.8 J$

Now by work energy equation we have

$\frac{1}{2}mv_i^2 + W_f + W_g = \frac{1}{2}mv_f^2$

$\frac{1}{2}0.5(12^2) - 9.8 - 22 = \frac{1}{2}(0.5)v_f^2$

$v_f = 4.1 m/s$

Part c)

now minimum speed required at the top is such that the normal force must be zero

$mg = \frac{mv^2}{R}$

$v = \sqrt{Rg}$

$v = 3.13 m/s$

so here we got speed more than the required speed so it will reach the top

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3 years ago

What is projectile motion caused by?

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Gravity acts to influence the vertical motion of the projectile, thus causing a vertical acceleration. The horizontal motion of the projectile is the result of the tendency of any object in motion to remain in motion at constant velocity.

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3 years ago

Read 2 more answers

1. Susan pushes her dad, David, on an ice rink with a force of 30 N. She weighs 45 kg and her dad weighs 100 kg. What are the ac

mamaluj [8]

Explanation:

Given parameters:

Force = 30N

Weight Susan = 45kg

Weight of Dad = 100kg

Unknown:

Acceleration of Susan = ?

Acceleration of Dad = ?

Solution:

Force = mass x acceleration

Acceleration = $\frac{force}{mass}$

Acceleration of Susan = $\frac{30}{45}$ = 0.67m/s²

Acceleration of Dad = $\frac{30}{100}$ = 0.3m/s²

Learn more:

Acceleration brainly.com/question/3820012

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3 years ago

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46.6666 that is the mass number

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2 years ago