Ask question

Ask question

All categories

3 years ago

13

a man can swim in still water with speed of 2kmhr-1 wants to cross a river 200m wide flowing with 1kmhr-1 . Calculate the time t

aken by the man to cross river in shortest time.

1 answer:

tangare [24]3 years ago

3 0

Answer:

d savage

Explanation:

You might be interested in

You are walking toward the back of a train that is moving forward with a constant velocity. The train's velocity relative to the

yawa3891 [41]

Answer:

28.5 m/s

Explanation:

There are 2 different velocities: the train velocity and yours velocity. They're in opposite directions, so one is positive and other is negative. Take the forward direction as the positive:

V = +30 -1.5

V = 28.5 m/s

7 0

3 years ago

Describe the energy conversion in each of these scenarios: a plant using photosynthesis to make food, using a battery-powered fl

fgiga [73]

Answer:

look it up

Explanation:

6 0

3 years ago

Solar cells change into electricity.

ValentinkaMS [17]

Answer:

yes that is true because if you put the solar thing in the sunlight it gets converted to electricity

3 0

3 years ago

Read 2 more answers

A 13 kg hanging sculpture is suspended by a 95-cm-long, 5.0 g steel wire. When the wind blows hard, the wire hums at its fundame

Artyom0805 [142]

Answer:

$f=81.96 \ Hz$

Explanation:

Givens

$L=95cm$

$m_{sculpture} =13kg$

$m_{wire}=5g$

The frequency is defined by

$f=\frac{v}{\lambda}$

Where $v$ is the speed of the wave in the string and $\lambda$ is its wave length.

The wave length is defined as $\lambda = 2L = 2(0.95m)=1.9m$

Now, to find the speed, we need the tension of the wire and its linear mass density

$v=\sqrt{\frac{T}{\mu} }$

Where $\mu=\frac{0.005kg}{0.95m}= 5.26 \times 10^{-3}$ and the tension is defined as $T=m_{sculpture} g=13kg(9.81 m/s^{2} )=127.53N$

Replacing this value, the speed is

$v=\sqrt{\frac{127.53N}{5.26 \times 10^{-3} } }=155.71 m/s$

Then, we replace the speed and the wave length in the first equation

$f=\frac{v}{\lambda}\\f=\frac{155.71 m/s}{1.9m}\\ f=81.96Hz$

Therefore, the frequency is $f=81.96 \ Hz$

3 0

3 years ago

Read 2 more answers

How much kinetic energy does a 1500 kg car have if it’s moving at 15 m/s

Tresset [83]

Answer:

Mass of car m = 1500 kg

velocity v = 15 m/s

kinetic energy = ½ mv2

= ½ x 1500 x (15)2

= 1687501 kg m2 /s2

= 168750J

Explanation:

6 0

3 years ago