25 PTS

When you rub a balloon on a sweater or your hair, the what is transferred to the balloon giving it a what charge. The balloon wi

Elis [28]

Answer:

When you rub a balloon on a sweater or your hair, the electrons are transferred to the balloon giving it a negative charge. The balloon will then repel any object that has a different charge.

hope this helps :)

5 0

3 years ago

Please help im failing!!!

natta225 [31]

1- Kinetic , Mass , Speed
2- Speed
3- Speed, Mass
4- Mass, More
5- Transferred, collide
6- Kinetic, electricity
7- Transferred, Destroyed

:)

5 0

3 years ago

A centrifugal pump discharges 300 gpm against a head of 55 ft when the speed is 1500 rpm. The diameter of the impeller is 15.5 i

Ksivusya [100]

Answer: Question 1: Efficiency is 0.6944

Question 2: speed of similar pump is 2067rpm

Explanation:

Question 1:

Flow rate of pump 1 (Q1) = 300gpm

Flow rate of pump 2 (Q2) = 400gpm

Head of pump (H)= 55ft

Speed of pump1 (v1)= 1500rpm

Speed of pump2(v2) = ?

Diameter of impeller in pump 1= 15.5in = 0.3937m

Diameter of impeller in pump 2= 15in = 0.381

B.H.P= 6.0

Assuming cold water, S.G = 1.0

eff= (H x Q x S.G)/ 3960 x B.H.P

= (55x 300x 1)/3960x 6

= 0.6944

Question 2:

Q = A x V. (1)

A1 x v1 = A2 x V2. (2)

Since A1 = A2 = A ( since they are geometrically similar

A = Q1/V1 = Q2/V2. (3)

V1(m/s) = r x 2π x N(rpm)/60

= (0.3937x 2 x π x 1500)/2x 60

= 30.925m/s

Using equation (3)

V2 = (400 x 30.925)/300

= 41.2335m/s

To rpm:

N(rpm) = (60 x V(m/s))/2 x π x r

= (60 x 41.2335)/ 2× π × 0.1905

= 2067rpm.

6 0

3 years ago

A sound wave produced by a clock chime is heard 400 m away 2.0 s later. The sound wave has a frequency of 512 Hz. What is its pe

emmasim [6.3K]

Answer:

$\frac{1}{512}$ seconds

Explanation:

T = 1 / f

where T is the period and f is frequency.

Here the frequency is 512 Hz.

Using the formula:

T = $\frac{1}{512}$ seconds

3 0

3 years ago

A 1200 kg car starts from rest and travels 100m in a time of 10 seconds . A) what is the acceleration of the car? B) what force

SVEN [57.7K]

Given:
Mass (m) = 1200 kg
Distance (s) = 100 m
Time (t) = 10 seconds
Now,
$velocity (v) = \frac{distance}{time}$

= $\frac{100~ m}{10~seconds}$

= 10 m/s
Note that this one is the final velocity.
We also know that,
initial velocity (u) = 0 m/s ....... because the car starts from rest.
Now,
$acceleration (a)= \frac{change~in~velocity}{time}$

= $\frac{v-u}{t}$

= $\frac{10-0}{10}$

= 1 m/s²
Now,
Force (F) = mass (m) * acceleration (a)
= 1200 kg * 1 m/s²
= 1200 kg.m/s²
= 1200 N
Now,
Work Done (W) = Force (F) * displacement (s) ....note that displacement is same as distance.
 = 1200 N * 100 m
 = 120000 N.m
= 120000 J
Now,
Power (P) = $\frac{Work~done(W)}{time(t)}$

= $\frac{120000~J}{10s}$

= 12000 J/s
= 12000 watt
SO,
A) The acceleration of the car is 1 m/s².
B) 1200 Newton (N) force must have acted on the car.
C) The velocity of the car after 10 seconds is 10 m/s.
D) 120000 Joule (J) work was done on the car.
E) The engine produced a minimum power of 12000 watt.

5 0

4 years ago