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3 years ago

What is the distance a truck can travel if it moves 7 m/s for 20 seconds?

2 answers:

8 0

If it moves 7 m/s and never slows down or speeds up, and it keeps doing this for 20 seconds, then it will cover 7 meters in the 1st second, 7 meters in the 2nd second, 7 meters in the 3rd second, 7 meters in the 4th second, 7 meters in the 5th second, and so on and so forth, twenty times. All together, it'll cover

7+7+7+7+7+7+7+7+7+7+7+7+7+7+7+7+7+7+7+7 meters

What I did there was: I wrote down ' 7 ' twenty times.

Now, there's a much easier way to write it.

In arithmetic, a little dot like this --> · <-- means "times", so we can write

20 · 7 and then we can work it out with our calculator or our pencil.

20 · 7 = <em> 140 meters</em> .

artcher [175]3 years ago

6 0

if it moves 7m/s, that means every second it goes 7m. Now we just multiply by the time (20 seconds) and end up with 140m.

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The amount of potential energy possessed by an elevated object is equal to

Sedbober [7]

Answer:

Potential energy of the object will be equal to mgh

Explanation:

Let the mass of the object is m

Acceleration due to gravity is $gm/sec^2$

Let the object is released from height h

We have to find the potential energy

Potential energy is of an object released from height h is equal to

$U=mgh$ , here m is mass, g is acceleration due to gravity and h is height from which object is released.

4 0

4 years ago

If a ball drops from 10ft after 5 seconds how high would the ball be. (For every second the ball loses 3ft) a bounce is half of

nlexa [21]

5ft I took the quiz/test.

3 0

3 years ago

Explain why the calorimeter must be insulated from its surroundings

mariarad [96]

To minimize loss of heat or absorption of heat from surroundings

7 0

3 years ago

Read the scenario and solve these two problems.

Burka [1]

Answers:

a) 5400000 J

b) 45.92 m

Explanation:

a) The kinetic energy $K$ of an object is given by:

$K=\frac{1}{2}mV^{2}$

Where:

$m=12000 kg$ is the mass of the train

$V=30 m/s$ is the speed of the train

Solving the equation:

$K=\frac{1}{2}(12000 kg)(30 m/s)^{2}$

$K=5400000 J$ This is the train's kinetic energy at its top speed

b) Now, according to the Conservation of Energy Law, the total initial energy is equal to the total final energy:

$E_{i}=E_{f}$

$K_{i}+P_{i}=K_{f}+P_{f}$

Where:

$K_{i}=5400000 J$ is the train's initial kinetic energy

$P_{i}=0 J$ is the train's initial potential energy

$K_{f}=0 J$ is the train's final kinetic energy

$P_{f}=mgh$ is the train's final potential energy, where $g=9.8 m/s^{2}$ is the acceleration due gravity and $h$ is the height.

Rewriting the equation with the given values:

$5400000 J=(12000 kg)(9.8 m/s^{2})h$

Finding $h$ :

$h=45.918 m \approx 45.92 m$

7 0

3 years ago

Read 2 more answers

At what speed does a clock move if it is measured to run at a rate two-fifths the rate of a clock at rest with respect to an obs

Liono4ka [1.6K]

Answer:

0.44c

Explanation:

We know that

Time interval at speed (ts)= time interval at rest(tr) / gamma

where

gamma = √[1-(v/c)²]

ts = tr / gamma

tr/ts = gamma

But

Ss/Sr = gamma

Where

Sr = clock speed at rest, Ss at speed):

√[1-(v/c)²] = 2/5

1 - (v/c)² = 4/25

(v/c)²= 5/25

v/c = √5 / 5

v = 0.444c

4 0

3 years ago