What is the weight of an object on the earth with a mass of 70 kg. <br> (g= 10 m/s2)

A 60.0 kg ballet dancer stands on her toes during a performance with four square inches (26.0 cm2) in contact with the floor. Wh

Anit [1.1K]

Answer:

Explanation:

Given

Mass of dancer $m=60\ kg$

Area of contact $A=26\ cm^2$

(a)If dancer is stationary

Pressure exerted by Floor is given by load per unit area of contact

$P=\frac{weight}{A}$

$P=\frac{mg}{A}$

$P=\frac{60\times 9.8}{26\times 10^{-4}}$

$P=226.153 kN$

(b)If dancer is leaping upwards with an acceleration of $a=5 m/s^2$

So apparent weight of dancer is $W'=mg+ma$

$W'=m(g+a)=60\cdot (9.8+5)$

$W'=888\ N$

$Pressure=\frac{W'}{A}$

$Pressure=\frac{888}{26\times 10^{-4}}$

$=341.53\ kN$

5 0

2 years ago

Help me with this Weather Station Model by answering 5 questions. It is due tomorrow.

Sav [38]

A is the answer to your question

7 0

3 years ago

Which planet orbits in a different plane than all of the others?

coldgirl [10]

Although they're all 'close', none of the planets orbits in the same plane as any other planet. They're all in slightly different planes.

The farthest out compared to all the others is Pluto, with an orbit inclined about 17 degrees compared to the ecliptic plane (Earth's orbit). But Pluto is officially not a planet, so I don't think it's a good answer.

The next greatest inclination compared to Earth's orbit is <em>Mercury</em>. That one is about 7 degrees.

The other six planets are all in different orbital planes inclined less than 7 degrees compared to Earth's orbit.

6 0

3 years ago

A solenoid coil with 22 turns of wire is wound tightly around another coil with 340 turns. The inner solenoid is 25.0 cm long an

LUCKY_DIMON [66]

Answer:

a) 1.34*10^-8 W

b) 1.18*10^-5 H

c) 20mV

Explanation:

a) To find the average magnetic flux trough the inner solenoid you the following formula:

$\Phi_B=BA=\mu_oNIA$

mu_o: magnetic permeability of vacuum = 4pi*10^-7 T/A

N: turns of the solenoid = 340

I: current of the inner solenoid = 0.100A

A: area of the inner solenoid = pi*r^2

r: radius of the inner solenoid = 2.00cm/2=1.00cm=10^-2m

You calculate the area and then replace the values of N, I, mu_o and A to find the magnetic flux:

$A=\pi(10^{-2}m)^2=3.141510^{-4}m^2\\\Phi_B=(4\pi*10^{-7}T/A)(340)(0.100A)(3.1415*10^{-4}m^2)=1.34*10^{-8}W\\$

the magnetic flux is 1.34*10^{-8}W

b) the mutual inductance is given by:

$M=\mu_o N_1 N_2 \frac{A_2}{l}$

N1: turns of the outer solenoid = 22

N2: turns of the inner solenoid

A_2: area of the inner solenoid

l: length of the solenoids = 25.0cm=0.25m

by replacing all these values you obtain:

$M=(4\pi*10^{-7}T/A)(340)(22)\frac{3.14*10^{-4}m^2}{0.25m}=1.18*10^{-5}H$

the mutual inductance is 1.18*10^{-5}H

c) the emf induced can be computed by using the mutual inductance and the change in the current of the inner solenoid:

$\epsilon_1=M\frac{dI_2}{dt}$

by replacing you obtain:

$\epsilon_1=(1.18*10^{-5}H)(1700A/s)=0.02V=20mV$

the emf is 20mV

7 0

3 years ago

Read 2 more answers

A 7.0kg object rests on a horizontal frictionless surface. What is the magnitude of the horizontal

sukhopar [10]

Answer:

16.1 N

Explanation:

From the question,

F = ma.............................. Equation 1

Where F = horizontal force, m = mass of the object, a = acceleration .

Given: m = 7.0 kg, a = 2.3 m/s²

Substitute this values into equation 1

F = (7.0×2.3)

F = 16.1 N.

Hence the magnitude of the horizontal force is 16.1 N

6 0

2 years ago

What is the weight of an object on the earth with a mass of 70 kg. (g= 10 m/s2)