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3 years ago

What is energy????????

Physics

1 answer:

Mashcka [7]3 years ago

4 0

Answer:

Energy is the ability to do work.

Explanation: Work is just the act of displaying something by applying force.

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A cyclist is travelling eastwards at a velocity of 40 ms and rain is falling vertically at a speed of 10 ms. Find the velocity o

Genrish500 [490]

41.23

v(B,E)=40 GOING EAST

V(R,E)=10 COMING DOWN

then 41.23

6 0

3 years ago

Jason has 13720 J of gravitational potential energy standing at the top of a cliff over the lake. If he jumps off the cliff and

Anna [14]

The conservation of energy and Newton's second law allows us to find the results about Jason's falling motion are;

The energy when reaching the water is K = 13720 J

The average force of the water to stop it is: F = 2744 N

<h3>Energy conservation.</h3><h3> </h3>

The conservation of energy is one of the most important principles of physics, stable that if there is no friction force, mechanical energy is conserved at all points.

Mechanical energy is the sum of kinetic energy plus potential energy.

Let's look for the energy at two points

Starting point. Get higher.

Em₀ = U = 13720 J

Final point. Lower down.

$Em_f$ = K

Friction in the air is negligible, so energy is conserved.

$Em_o= Em_f$

K = 13720J

<h3>Kinematics and Newton's law.</h3><h3> </h3>

They indicate that it stops 5m under the water, if we assume that the water acts with a constant force, we can use kinematics and Newton's second law to find this force.

The kinematics expression to find the acceleration is

v² =v₀² – 2ay

When it stops the speed is zero.

$a = \frac{v_o^2}{2y}$

Newton's second law is:

F = ma

F = m ( $\frac{v_o^2}{2y}$ )

The expression for the kinetic energy is:

K = ½ m v₀²

$v_o^2 = \frac{2K}{m}$

Let's substitute.

F = $m (\frac{2K}{m}) \frac{1}{2y}$

$F= \frac{K}{y}$

Let's calculate.

F= $\frac{13720}{5}$

F = 2744N

In conclusion using conservation of energy and Newton's second law we can find the results about Jason's falling motion are;

The energy when reaching the water is K = 13720 J

The average force of the water to stop it is: F = 2744 N

Learn more about energy here: brainly.com/question/14274074

6 0

2 years ago

A uniform metal bar 100cm long balances at 20cm mark when a mass of 1.5kg is attached at 0cm mark calculate the weight of the ba

beks73 [17]

Answer:

30 N

Explanation:

there are two forces act on the bar:

- weight of 1.5 kg mass, w = mg = 15 N

- weight of the bar, wb

for balance,

w * Lw = wb * Lwb

Lw = length of bar from the mass to the pivot

Lwb = lenght of bar from the center of the bar to the pivot

15 * 20 = wb * (50-20)

300 = wb * 30

wb = 300/30 = 30 N

4 0

4 years ago

A steel plate weighing 180 lb with center of gravity at point G is supported by a roller at point A, a bar DE, and a horizontal

melamori03 [73]

Answer:

Therefore, the force supported by the hydraulic cylinder is = -70.01 lb

Thus, the force supported by the bar = -233.84 lb

The reaction force supported by the reaction of the roller = 341.31 lb

Explanation:

The attached diagrams is shown in the file below:

From there; taking moments about point A

$\sum M__A }=0$

- 40 (180) - (80) $F_E$ Cos 37° + 55

-7200 + $F_E$ (-80 Cos 37° + 55 sin 37° ) = 0

= - 7200 - 30.79 $F_E$

- 30.79 $F_E$ = 7200

$F_E$ = $-\frac{7200}{30.79}$

$F_E$ = -233.84 lb

Thus, the force supported by the bar = -233.84 lb

Taking the equilibrium of forces in the vertical direction

$\sum f_y = 0$

$F_E$ sin 37 + $F_A$ cos 20 - $F_G$ = 0

- 233.84 sin 37 + $F_A$ cos 20 - 180 = 0

$F_A$ cos 20 = 320.73

$F_A$ = $\frac{320.73}{cos 20}$

$F_A$ = 341.31 lb

The reaction force supported by the reaction of the roller = 341.31 lb

Taking the equilibrium of forces on the horizontal direction.

$\sum f_y = 0$

$F_E$ cos 37 - $F_{CB} + F_A$ sin 20° = 0

-233.84 cos 37 - $F_{CB}$ + 341.31 sin 20° = 0

-186.75 - $F_{CB}$ + 116.74 = 0

- $F_{CB}$ -70.01 = 0

- $F_{CB}$ = 70.01

$F_{CB}$ = - 70.01 lb

Therefore, the force supported by the hydraulic cylinder is = -70.01 lb

7 0

4 years ago

A substance with a density of 16.8 g/ml has a mass of 3.2 g. what is its volume?

wel

We know that d=m/v where d is density, m is mass and v is volume. Lets transform formula to get v in times of d and m
$d= \frac{m}{V} /*V \\ V*d=m /:d \\ V= \frac{m}{d}$
Now we have to substitute our data to formula
V= $\frac{3.2}{16.8}=0.19$ ml - its the answeer

4 0

3 years ago

Read 2 more answers