All categories

2 years ago

An object is moving at a constant velocity of 10 m/s for 5 seconds. What is

Physics

1 answer:

german2 years ago

3 0

initial velocity (u)=0m/s

final velocity (v)=10m/s

time( t)=5s

acceleration (a)=v-u÷t

acceleration (a)=10-0÷5

acceleration (a)=10÷5

acceleration (a)=2

therefore acceleration (a)=2m/s

You might be interested in

Under which one of the following circumstances will heat transfer occur via convection? Group of answer choices Convection occur

BartSMP [9]

Answer:

1) in metal object heat transfer through the conduction .In vacuum heat transfer through only radiation .

In only gaseous state or in liquid state the heat transfer through convection hence option D is correct

8 0

3 years ago

Read 2 more answers

A capacitor with an initial potential difference of 100 V isdischarged through a resistor when a switch between them is closed a

jonny [76]

Answer:

(a). The time constant of the circuit is 2.17.

(b). The potential difference across the capacitor at t=17.0 s is 0.0396 V.

Explanation:

Given that,

Initial potential difference = 100 V

Potential difference across the capacitor = 1.00 V

(a). We need to calculate the time constant of the circuit

Using formula of potential difference

$V(t)=V_{0}e^{\dfrac{-t}{RC}}$

Put the value into the formula

$1.00=100e^{\dfrac{-10.0}{RC}}$

$0.01=e^{\dfrac{-10.0}{RC}}$

On taking ln

$ln(0.01)=\dfrac{-10}{RC}$

$RC=\dfrac{-10}{ln(0.01)}$

$RC=2.17$

(b). We need to calculate the potential difference across the capacitor at t=17.0 s

Using formula again

$V(17)=100e^{\dfrac{-17}{2.17}}$

$V{17}=0.0396\ V$

Hence, (a). The time constant of the circuit is 2.17.

(b). The potential difference across the capacitor at t=17.0 s is 0.0396 V.

7 0

3 years ago

Steam flows steadily through an adiabatic turbine. The inlet conditions of the steam are 4 MPa, 500°C, and 80 m/s and the exit c

FrozenT [24]

Answer:

a) $\Delta \dot K = 24.570\,kW$ , b) $\dot W_{out} = 12729.15\,kW$ , c) $A_{in} = 0.0136\,m^{2}$

Explanation:

A turbine is a device which works usually in steady state and assumption of being adiabatic means no heat interactions between steam through turbine and surroudings and produce mechanical work from fluid energy. Changes in gravitational energy can be neglected. This system can be modelled after the First Law of Thermodynamics:

$-\dot W_{out} + \dot m \cdot (h_{in} - h_{out}) + \frac{1}{2}\cdot \dot m \cdot (v_{in}^{2}-v_{out}^{2}) = 0$

a) Change in kinetic energy

$\Delta \dot K = \frac{1}{2}\cdot \dot m \cdot (v_{in}^{2} - v_{out}^{2})$

$\Delta \dot K = \frac{1}{2} \cdot \left(12.6\,\frac{kg}{s} \right) \cdot \left[\left(80\,\frac{m}{s} \right)^{2}-\left(50\,\frac{m}{s} \right)^{2}\right]$

$\Delta \dot K = 24570\,W$

$\Delta \dot K = 24.570\,kW$

b) Power output

$\dot W_{out} = \dot m \cdot (h_{in} - h_{out}) + \frac{1}{2}\cdot \dot m \cdot (v_{in}^{2}-v_{out}^{2})$

$\dot W_{out} = \left(12.6\,\frac{kg}{s}\right)\cdot \left(3446\,\frac{kJ}{kg} - 2437.7\,\frac{kJ}{kg} \right) + 24.570\,kW$

$\dot W_{out} = 12729.15\,kW$

c) Turbine inlet area

Turbine inlet area can be found by using the following expressions:

$\dot V_{in} = \dot m \cdot \nu_{in}$

$\dot V_{in} = \left(12.6\,\frac{kg}{s}\right) \cdot \left(0.086442\,\frac{m^{3}}{kg} \right)$

$\dot V_{in} = 1.089\,\frac{m^{3}}{s}$

$A_{in} = \frac{\dot V_{in}}{v_{in}}$

$A_{in} = \frac{1.089\,\frac{m^{3}}{s} }{80\,\frac{m}{s} }$

$A_{in} = 0.0136\,m^{2}$

8 0

3 years ago

For a freely falling object dropped from rest, what is the acceleration at the

Zinaida [17]

The acceleration of the object after 3 seconds of fall is -9.8 m/s².

The given parameters;

initial velocity of the object, u = 0
time of motion of the object, t = 3 seconds

Acceleration is the change in velocity per change in time of motion.

The acceleration of the object after 3 seconds of fall is calculated as follows;

Since the object is in free fall, the object experiences only acceleration due to gravity.
the magnitude of this acceleration due to gravity is 9.8 m/s²
the direction of this acceleration is downwards

Thus, the acceleration of the object after 3 seconds of fall is -9.8 m/s².

Learn more here: brainly.com/question/13197713

7 0

2 years ago

You find it takes 200 J of heat to take 4 kg of an unknown substance from 200 K to 240 K. It does not change phases during this

klasskru [66]

Answer:

300 K

Explanation:

First, we have find the specific heat capacity of the unknown substance.

The heat gained by the substance is given by the formula:

H = m*c*(T2 - T1)

Where m = mass of the substance

c = specific heat capacity

T2 = final temperature

T1 = initial temperature

From the question:

H = 200J

m = 4 kg

T1 = 200K

T2 = 240 K

Therefore:

200 = 4 * c * (240 - 200)

200 = 4 * c * 40

200 = 160 * c

c = 200/160

c = 1.25 J/kgK

The heat capacity of the substance is 1.25 J/kgK.

If 300 J of heat is added, the new heat becomes 500 J.

Hence, we need to find the final temperature, T2, when heat is 500 J.

Using the same formula:

500 = 4 * 1.25 * (T2 - 200)

500 = 5 * (T2 - 200)

100 = T2 - 200

=> T2 = 100 + 200 = 300 K

The new final temperature of the unknown substance is 300K.

7 0

3 years ago