All categories

4 years ago

Two forces of 5N and 7N respectively act on an object.when will the resultant of two vectors be at a minimum?

2 answers:

7 0

When the two forces are acting in the opposite direction, then the resultant of the two vectors will be at a minimum. The value of the force will be either 2 Newton or -2 newton. . It is the simplest way to prove and explain the situation under which the resultant of the two vectors will be at a minimum. The situation under which the resultant of the two vectors will be maximum is when the two forces of 5N and 7n will act in the same direction and create a combines force of 12N.

Dahasolnce [82]4 years ago

7 0

When the forces act in opposite directions

You might be interested in

during a _____, a substance mixes with another substance and changes into completely new substances with different properties.

Tatiana [17]

chemical change or chemical reaction

7 0

4 years ago

How do u calculate momentum

Helga [31]

Answer:

Explanation:

To calculate the momentum of a moving object multiply the mass of the object times its velocity. The symbol for momentum is a small p. So, the momentum of the object is calculated to be 8.0 kg-m/s. Note the unit for momentum.

5 0

3 years ago

Two objects each moving with speed v travel in opposite directions along a straight line passing through both their centers. The

Tpy6a [65]

Answer:

$\dfrac{1}{16}$

$\dfrac{5}{3}$

Explanation:

$m_1$ = Mass of first object

$m_2$ = Mass of second object

v = Speed of both objects

$\dfrac{v}{4}$ = Combined velocity

The ratio of final kinetic energy to initial kinetic energy will be

$\dfrac{K_f}{K_i}=\dfrac{\dfrac{1}{2}(m_1+m_2)(\dfrac{v}{4})^2}{\dfrac{1}{2}(m_1v^2+m_2v^2)} \\\Rightarrow \dfrac{K_f}{K_i}=\dfrac{(m_1+m_2)\dfrac{v^2}{16}}{m_1v^2+m_2v^2}\\\Rightarrow \dfrac{K_f}{K_i}=\dfrac{(m_1+m_2)\dfrac{1}{16}}{m_1+m_2}\\\Rightarrow \dfrac{K_f}{K_i}=\dfrac{1}{16}$

The ratio is $\dfrac{1}{16}$

As the linear momentum is conserved

$m_1v-m_2v=(m_1+m_2)\dfrac{v}{4}\\\Rightarrow m_1-m_2=(m_1+m_2)\dfrac{1}{4}$

Divide by $m_2$ on both sides

$\dfrac{m_1}{m_2}-1=\dfrac{m_1}{4m_2}+\dfrac{1}{4}\\\Rightarrow \dfrac{m_1}{m_2}-\dfrac{m_1}{4m_2}=\dfrac{1}{4}+1\\\Rightarrow \dfrac{3m_1}{4m_2}=\dfrac{5}{4}\\\Rightarrow \dfrac{m_1}{m_2}=\dfrac{5\times 4}{3\times 4}\\\Rightarrow \dfrac{m_1}{m_2}=\dfrac{5}{3}$

The ratio of mass is $\dfrac{5}{3}$

6 0

3 years ago

A jogger is running outdoors on a cold day when the temperature is -20.0°C. She is breathing at the rate of 25 breaths per minut

Katyanochek1 [597]

Answer: 168606 J

Explanation:

Amount of heat lost is given by:

Q = m c ΔT

where, m is the mass of air inhaled, c is the specific heat of air and ΔT is the change in the temperature.

First, we will calculate the mass of air inhaled.

In each breath, jogger inhales 0.00450 m³ of air.

Breathing rate = 25 breathes per minute.

She jogs for 20 minutes.

So amount of air inhaled = 25 breathes per minute × 20 minutes × 0.00450 m³

Mass of air inhaled = density of air × volume of air inhaled

⇒ m = 1.29 kg/m³× 25 breathes per minute × 20 minutes × 0.00450 m³

⇒ m = 2.9 kg

Now, ΔT = T₂-T₁

T₁ = -20⁰C = -20 +273 K = 253 K

T₂ = 37⁰C = 37+273 K = 310 K

⇒ ΔT = T₂-T₁ = 310 K- 253 K = 57 K

Q = m c ΔT

⇒ Q = 2.9 kg × 1020 J/kg.K × 57 K = 168606 J

Thus, the jogger losses 168606 J amount of heat from breathing during 20 minutes of jogging.

3 0

4 years ago

How powerful is a mobile charger with an output voltage of 5V and a current of 2A?

yulyashka [42]

Answer:

P = 10 Watts

Explanation:

Given that,

The voltage of a mobile charger, V = 5 V

Current, I = 2 A

We need to find the power of the charger. The formula for the electric power is given by:

P = VI

So,

$P=5\ V\times 2\ A\\\\P=10\ W$

So, the power of the mobile charge is 10 watts.

7 0

3 years ago