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3 years ago

A commuter backs her car out of her garage with an acceleration of . (a) How long does it take her to reach a speed of 2.00 m/s

1 answer:

3 0

Question: A commuter backs her car out of her garage with an acceleration of 1.4 m/s² (a) How long does it take her to reach a speed of 2.00 m/s

Answer:

1.43 s

Explanation:

Applying,

a = (v-u)/t........... Equation 1

Where a = acceleration, v = final velocity, u = initial velocity, t = time

make t the subject of the equation

t = (v-u)/a........... Equation 2

From the question,

Given: v = 2 m/s, u = 0m/s (from rest), a = 1.4 m/s²

Substitute into equation 2

t = (2-0)/1.4

t = 1.43 s

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The velocity of any object depends upon

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The displacement, time, and direction

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3 years ago

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When cooking frozen cheese ravioli, the directions say to put the 255 grams of filled pasta into 3 quarts of boiling water. Why

nadya68 [22]

Answer:

a. $T_f=95.14^{\circ}C$

b. $T_f=86.4^{\circ}C$

It is asked for 3 quarts of water because it prevents the temperature drop.

Explanation:

Given:

mass of frozen cheese, $m_c=255\ g$

quantity of water suggested for the given cheese, $m_w=3\ quarts\times 946.35=2839.05\ g$

initial temperature of cheese, $T_{ic}=-40^{\circ}\ C$

specific heat of cheese, $c_c=0.4\ cal.g^{-1}.^{\circ}C^{-1}$

initial temperature of water, $T_{iw}=100^{\circ}\ C$

we have specific heat of water, $c_w=1\ cal.g^{-1}.^{\circ}C^{-1}$

so now, we use the heat equation to find the amount of heat exchange during the process:

$m_c\times c_c\times \Delta T=m_w\times c_w\times \Delta T$

$255\times 0.4\times (T_f-(-40))=2839.05\times 1\times (100-T_f)$

$T_f=95.14^{\circ}C$

when using 1 quart of water:

$255\times 0.4\times (T_f-(-40))=946.35\times 1\times (100-T_f)$

$T_f=86.4^{\circ}C$

It is asked for 3 quarts of water because it prevents the temperature drop.

3 0

3 years ago

PLS HELP BEING TIMED!!!

Elodia [21]

Answer:

$K_{i}+U_{g,i} = K_{f}+U_{g,f}$

Explanation:

A closed system is a system where exists energy interactions with surroundings, but not mass interactions. If we neglect any energy interactions from boundary work, heat, electricity, magnetism and nuclear phenomena and assume that process occurs at steady state and all effects from non-conservative forces can be neglected, then the equation of energy conservation is reduce to this form:

$\Delta K +\Delta U_{g} = 0$ (1)

Where:

$\Delta K$ - Change in kinetic energy of the system, measured in joules.

$\Delta U_{g}$ - Change in gravitational potential energy of the system, measured in joules.

If we know that $\Delta K=K_{i}-K_{f}$ and $\Delta U_{g} = U_{g,i}-U_{g,f}$ , then we get the following equation:

$K_{i}+U_{g,i} = K_{f}+U_{g,f}$ (2)

Where $i$ and $f$ stands for initial and final states of each energy component.

Hence, the right answer is $K_{i}+U_{g,i} = K_{f}+U_{g,f}$

7 0

3 years ago

Read 2 more answers

a 0.0780 kg lemming runs off a 5.36 m high cliff at 4.84 m/s. what is its kinetic energy(KE) when it jumps PLEASE HELP ME

Kay [80]

Answer:

0.91 J

Explanation:

The kinetic energy of an object is given by

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

where

m is the mass of the object

v is its speed

For the lemming in this problem, when he jumps, we have:

m = 0.0780 kg is the mass

v = 4.84 m/s is the speed

Substituting into the equation, we find:

$K=\frac{1}{2}(0.0780)(4.84)^2=0.91 J$

8 0

3 years ago

Select the correct answer.<br> Which type of energy is thermal energy a form of

elena-s [515]

Kinetic energy. thermal energy (a low form of energy ) is a form of kinetic energy as it is produced as a result of motion of particles either if they vibrate at their position or they move along longer paths. Motion produces friction or resistance which leads to excitation and thus the heat is produced. The higher the motion of the particles, the higher would be the thermal energy.

7 0

3 years ago