Ask question

Ask question

All categories

sleet_krkn [62]

2 years ago

8

A man has a power of 90 W and mass 60 kg runs up a staircase in 40 s. If each staircase is 20cm high find the number of steps? (

grade 9 physics-GRAVITATION)

1 answer:

Svetlanka [38]2 years ago

4 0

I depends on three area of the staircase

You might be interested in

An all-electric car (not a hybrid) is designed to run from a bank of 12.0 V batteries with total energy storage of 2.30 ✕ 107 J.

AnnyKZ [126]

Answer:

a) $I=733.33\ A$

b) $d=52272.7273\ m$

c) $d'=51948.0519\ m$

Explanation:

Given:

voltage of the battery, $V=12\ V$

energy storage capacity of the battery, $E=2.3\times 10^7\ J$

speed of the car, $v=20\ m.s^{-1}$

a)

power drawn by the car, $P=8.8\ kW$

<u>Now the Current delivered to the motor:</u>

we the relation between the power and electrical current,

$P=V.I$

$8800=12\times I$

$I=733.33\ A$

b)

<u>Distance travelled before battery is out of juice:</u>

we first find the time before the battery runs out,

$t=\frac{E}{P}$

$t=\frac{2.3\times 10^7}{8800}$

$t=2613.636\ s$

Now the distance:

$d=v.t$

$d=20\times 2613.636$

$d=52272.7273\ m$

c)

When the head light of 55 W power is kept on while moving then the power consumption of the car is:

$P'=P+55$

$P'=8800+55$

$P'=8855\ W$

<u>Now the time of operation of the car:</u>

$t'=\frac{E}{P'}$

$t'=\frac{2.3\times 10^7}{8855}$

$t'=2597.4026\ s$

<u>Now the distance travelled:</u>

$d'=v.t'$

$d'=20\times 2597.4025$

$d'=51948.0519\ m$

5 0

3 years ago

What is the purpose of chloroplasts, and why do you think it is missing from the root hair cell?

Karolina [17]

Explanation:

Mitochondria are essential parts of many eukaryotes, but they are useless without oxygen. Therefore, chloroplasts are extremely important. They produce breathable air for life. Root hairs are seen to not have chloroplasts as their job is to collect water and nutrients.

<h2><em><u>BRAINILIEST</u></em><em><u> </u></em><em><u>PLEASE</u></em><em><u> </u></em></h2>

8 0

3 years ago

A technician wraps wire around a tube of length 38 cm having a diameter of 8.3 cm. When the windings are evenly spread over the

seropon [69]

Answer:

The inductance of this solenoid is 5.51 mH.

Explanation:

Given that,

length of the tube, l = 38 cm = 0.38 m

Diameter of the tube, d = 8.3 cm

Radius of the tube, r = 4.15 cm

The number of turns, N = 555

We need to find the inductance of this solenoid. It is given by the formula as :

$L=\dfrac{\mu N^2A}{l}\\\\L=\dfrac{4\pi \times 10^{-7}\times 555^2\times \pi \times (4.15\times 10^{-2})^2}{0.38}\\\\L=0.00551\ H\\\\L=5.51\ mH$

So, the inductance of this solenoid is 5.51 mH. Hence, this is the required solution.

7 0

3 years ago

A box is 30cm wide , 50cm long and 20cm high Calculate :

stellarik [79]

Answer:

A) 1500cm ^2

B) 30000 CM ^3

7 0

3 years ago

A car and a delivery truck both start from rest and accelerate at the same rate. However, the car accelerates for twice the amou

andriy [413]

C. because the car traveled twice as long at the same rate as the truck

5 0

3 years ago

Read 2 more answers