Can been seen but not projected?

The kinetic energy of an object with a mass of 6.8 kg and a velocity of 5.0 m/s is J. (Report the answer to two significant figu

abruzzese [7]

Answer:

$\boxed{\sf Kinetic \ energy \ (KE) = 85 \ J}$

Given:

Mass (m) = 6.8 kg

Speed (v) = 5.0 m/s

To Find:

Kinetic energy (KE)

Explanation:

Formula:

$\boxed{ \bold{\sf KE = \frac{1}{2} m {v}^{2} }}$

Substituting values of m & v in the equation:

$\sf \implies KE = \frac{1}{2} \times 6.8 \times {5}^{2}$

$\sf \implies KE = \frac{1}{ \cancel{2}} \times \cancel{2} \times 3.4 \times 25$

$\sf \implies KE =3.4 \times 25$

$\sf \implies KE = 85 \: J$

8 0

3 years ago

Read 2 more answers

A rectangular tank is filled to a depth of 10m with freshwater and open to air at atmospheric pressure.

charle [14.2K]

Answer:

1. 39068.07 N

2. 19534.036 N

Explanation:

depth of water h = 10 m

atmospheric pressure Patm = 101325 Pa

density of water p = 1000 kg/m^3

acceleration due to gravity g = 9.81 m/s^2

pressure due to depth of water = pgh

P = 1000 x 9.81 x 10 = 98100 Pa

total pressure on the bottom of the tank is Patm + p = 101325 + 98100 = 199425 Pa

Left plug has diameter = 50 cm = 0.5 m

radius = 0.5/2 = 0.25 m

height = 1 cm = 0.01 m

height below tank surface = 10 - 0.01 = 9.99

pressure at this depth = 1000 x 9.81 x 9.99 = 98001.9 Pa

total pressure = Patm + P = 101325 + 98001.9 = 199326.9 Pa

surface area of plug = π $r^{2}$ = 3.142 x $0.25^{2}$ = 0.196 $m^{2}$

force required to lift left plug = pressure x area

F = 199326.9 x 0.196 = 39068.07 N

The right side is a hemisphere with the same diameter, therefore surface area is half of the left plug

A = 0.196/2 = 0.098 $m^{2}$

force F required to lift right plug = 199326.9 x 0.098 = 19534.036 N

6 0

3 years ago

In an RC circuit, what fraction of the final energy is stored in an initially uncharged capacitor after it has been charging for

4vir4ik [10]

Answer:

The fraction fraction of the final energy is stored in an initially uncharged capacitor after it has been charging for 3.0 time constants is

$k = 0.903$

Explanation:

From the question we are told that

The time constant $\tau = 3$

The potential across the capacitor can be mathematically represented as

$V = V_o (1 - e^{- \tau})$

Where $V_o$ is the voltage of the capacitor when it is fully charged

So at $\tau = 3$

$V = V_o (1 - e^{- 3})$

$V = 0.950213 V_o$

Generally energy stored in a capacitor is mathematically represented as

$E = \frac{1}{2 } * C * V ^2$

In this equation the energy stored is directly proportional to the the square of the potential across the capacitor

Now since capacitance is constant at $\tau = 3$

The energy stored can be evaluated at as

$V^2 = (0.950213 V_o )^2$

$V^2 = 0.903 V_o ^2$

Hence the fraction of the energy stored in an initially uncharged capacitor is

$k = 0.903$

4 0

3 years ago

Identify each picture as either an inelastic collision or elastic collision

Ivan

Answer:

Inelastic collision:

A collision in which there is a loss of Kinetic Energy due to internal friction of the bodies colliding.

Characteristics of an inelastic collision:

the momentum of the system is conserved
the momentum of the system is conservedloss of kinetic energy

In a perfectly elastic collision, the two bodies that collide with each other stick together.

Elastic collision:

A collision in which the kinetic energy of the two bodies, before and after the collision, remains the same.

Characteristics of elastic collision:

the momentum of the system is conserved
no loss of kinetic energy

In everyday life, no collision is perfectly elastic.

__________________

ANSWER:

Given examples:

Two cars colliding with each other form an example of inelastic collision.

Reason:

(They lose kinetic energy and come to a stop after the collision.)

A ball bouncing after colliding with a surface is an example of elastic collision

Reason:

(a very less amount of kinetic energy is lost)

7 0

2 years ago

Students are asked to create roller coasters for marbles. Their goal is to design a coaster with the tallest possible hill that

ivann1987 [24]

Answer:

Kinetic Energy.

Explanation:

The movement of a roller coaster is accomplished by the conversion of potential energy to kinetic energy. The roller coaster cars gain potential energy as they are pulled to the top of the first hill. As the cars descend the potential energy is converted to kinetic energy.

3 0

3 years ago