I can't understand

Water is flowing through a channel that is 12m wide with a

Alexus [3.1K]

Answer:

Velocity from second channel will be 1.6875 m/sec

Explanation:

We have given width of the channel , that is diameter of the channel 1 $d_1$ = 12 m

So radius $r_1=\frac{d_1}{2}=\frac{12}{2}=6m$

Speed through the channel 1 $v_1=0.75m/sec$

Width , that is diameter of the channel 2 $d_2=4m$

So $r_2=2m$

From continuity equation

$A_1v_1=A_2v_2$

$\pi \times 12^2\times 0.75=4\times \pi\times 4^2\times v_2$

$v_2=1.6875m/sec$

So velocity from smaller channel will be 1.6875 m /sec

6 0

3 years ago

A 90-meter train travels at a constant speed of 10 meters per second. How long will it take to cross a 0.06 bridge?

salantis [7]

Answer:

The time taken for the train to cross the bridge is 9.01 s

Explanation:

Given;

length of the train, L₁ = 90 m

length of the bridge, L₂ = 0.06 m

speed of the train, v = 10 m/s

Total distance to be traveled, = L₁ + L₂

= 90 m + 0.06 m

= 90.06 m

Time of motion = Distance / speed

Time of motion = 90.06 / 10

Time of motion = 9.006 s ≅ 9.01 s

Therefore, the time taken for the train to cross the bridge is 9.01 s

5 0

3 years ago

The surface air pressure on the planet mars is about 0.007 atm. if you were standing on mars, the surface air pressure would be

Lelu [443]

Surface air pressure is a consequence of the weight of the air acting on its surface. For example, if you are standing on Mars, the pressure around you is what you call the surface air pressure. Thus, that surface air pressure must be 0.007 atm.

5 0

3 years ago

Block A, with a mass of 4.0 kg, is moving with a speed of 3.0 m/s while block B, with a mass of 6.0 kg, is moving in the opposit

ElenaW [278]

Answer:

The momentum of the two-block system is 18 kg-m/s

Explanation:

It is given that,

Mass of block A, $m_A=4\ kg$

Mass of block B, $m_B=6\ kg$

Velocity of block A, $v_A=3\ m/s$

Velocity of block B, $v_B=-5\ m/s$ (it is moving in opposite direction)

We need to find the momentum of two block system. It is given by the product of mass and velocity for both blocks i.e.

$p=m_Av_A+m_Bv_B$

$p=4\ kg\times 3\ m/s+6\ kg\times (-5\ m/s)$

p = -18 kg-m/s

So, the momentum of two block system is 18 kg-m/s. Hence, this is the required solution.

5 0

3 years ago

67. The formula to calculate a rate is r =

Over [174]

Answer:

a) d = r *t

Explanation:

The equivalent formula for calculating rate is given as:

d = r *t

Where d is the amount of substance, r is the rate and t is the time taken.

The rate of process is the amount or quantity attained per unit of time.

It is usually expressed as;

r = $\frac{d}{t}$

So, the other variant will be d = r *t

4 0

3 years ago