All categories

3 years ago

Hilda pushes her sofa across the room with a force of 40 N. It accelerates at 2 m/s/s. What is the mass of the sofa?

Physics

2 answers:

kicyunya [14]3 years ago

6 0

The correct answer of this question is : A) 20 Kg and B) 3 seconds.

EXPLANATION :

As per the first question, the force applied on sofa F = 40 N.

The acceleration of the sofa a = $2\ m/s^2$ .

We are asked to calculate the mass of the sofa.

From Newton's second law, we know that external unbalanced force is equal to the product of mass with acceleration of the body.

Mathematically force F = ma.

Hence, mass of the sofa is calculated as -

mass of sofa m = $\frac{F}{a}$

= $\frac{40}{2}\ Kg$

= 20 Kg.

As per the second question, initial velocity u = 2 m/s due west.

The final velocity of the skateboard v = 8 m/s.

The acceleration of the skate board a = $2\ m/s^2$

The time taken [ t ] to reach that velocity is calculated as -

From equation of kinematics, we know that -

v = u + at

⇒8 = 2 + 2t

⇒ 2t = 6

⇒ t = $\frac{6}{2}\ s$

⇒t = 3 s. [ans]

GalinKa [24]3 years ago

4 0

The first answer to the first question is 20 kg
the second answer to the second question is 3 seconds

You might be interested in

The electrons in the beam of a television tube have an energy of 19.0 keV. The tube is oriented so that the electrons move horiz

igomit [66]

Answer:

The direction is due south

Explanation:

From the question we are told that

The energy of the electron is $E = 19.0keV = 19.0 *10^3 eV$

The earths magnetic field is $B = 42.3 \muT = 42.3 *10^{-6} T$

Generally the force on the electron is perpendicular to the velocity of the elecrton and the magnetic field and this is mathematically reresented as

$\= F = q (\= v * \=B)$

On the first uploaded image is an illustration of the movement of the electron

Looking at the diagram we can see that in terms of direction the magnetic force is

$\= F =q(\=v * \= B)= -( -\r i * - \r k)$

$= -(- (\r i * \r k))$

generally i cross k = -j

so the equation above becomes

$\= F = -(-(- \r j))$

$= - \r j$

This show that the direction is towards the south

3 0

3 years ago

To improve your cardiovascular fitness:

RoseWind [281]

C.Perform push ups and curl-ups daily

4 0

3 years ago

Read 2 more answers

How much heat is needed to raise the temperature of an empty 2.0 x 101 kg vat made of

scZoUnD [109]

Answer:

Q = 7272 Kilojoules.

Explanation:

<u>Given the following data;</u>

Mass = 2.0*101kg = 202kg

Initial temperature, T1 = 10°C

Final temperature, T2 = 90°C

We know that the specific heat capacity of iron = 450J/kg°C

*To find the quantity of heat*

Heat capacity is given by the formula;

$Q = mcdt$

Where;

Q represents the heat capacity or quantity of heat.

m represents the mass of an object.

c represents the specific heat capacity of water.

dt represents the change in temperature.

dt = T2 - T1

dt = 90 - 10

dt = 80°C

Substituting the values into the equation, we have;

$Q = 202*450*80$

Q = 7272KJ or 7272000 Joules.

6 0

3 years ago

Energy cannot be created nor destroyed. A. Ella said "a lot of energy in the hot water has disappeared." Explain why her stateme

harkovskaia [24]

Answer:

See Explanation

Explanation:

The principle of conservation of energy states that; energy can neither be created nor destroyed but is converted from one form to another.

In view of this principle, Ella can not be correct when she says that a lot of energy has disappeared. The use of the term "disappeared" connotes the idea that the energy no longer exists which does not happen.

Hence, energy can not "disappear" from hot water rather the energy in the water may be transferred to the surroundings.

6 0

3 years ago

Which statement correctly describes how thermal energy tends to spontaneously flow?

True [87]

The answer is A. Heat flows from high to low. For example, when you put an ice cube in a hot drink, the heat from the drink goes to the ice cube, and that is why it melts.

5 0

3 years ago

Read 2 more answers