What is the mass number of this atom? Model Atom w A. 8 B. 16 C. 24

How long will it take a 2190 W motor to lift a 1.47 x 104 g box, 6.34 x 104 mm vertically.

-BARSIC- [3]

Answer:

4.2s

Explanation:

Given parameters:

Power = 2190W

Mass of box = 1.47 x 10⁴g

distance = 6.34 x 10⁴mm

Unknown:

Time = ?

Solution:

Power is the rate at which work is done;

Mathematically;

Power = $\frac{work done}{time}$

Time = $\frac{work done}{power}$

Work done = weight x height

convert mass to kg;

100g = 1kg;

1.47 x 10⁴g = 14.7kg

convert the height to m;

1000mm = 1m

6.34 x 10⁴mm gives 63.4m

Work done = 14.7 x 9.8 x 63.4 = 9133.4J

Time taken = $\frac{9133.4}{2190}$ = 4.2s

6 0

3 years ago

A racecar drives at a constant speed down a straight track. The car is in _?_

vagabundo [1.1K]

Answer:

the answer is

the car is in motion

7 0

3 years ago

A certain type of laser emits light that has a frequency of 4.2 × 1014 Hz. The light, however, occurs as a series of short pulse

bogdanovich [222]

Explanation:

It is given that,

Frequency of the laser light, $f=4.2\times 10^{14}\ Hz$

Time, $t=3.2\times 10^{-11}\ s$

(a) Let $\lambda$ is the wavelength of this light. It can be calculated as :

$\lambda=\dfrac{c}{f}$

$\lambda=\dfrac{3\times 10^8}{4.2\times 10^{14}}$

$\lambda=7.14\times 10^{-7}\ m$

or

$\lambda=714\ nm$

(b) Let n is the number of the wavelengths in one pulse. It can be calculated as :

$n=f\times t$

$n=4.2\times 10^{14}\times 3.2\times 10^{-11}$

n = 13440

Hence, this is the required solution.

8 0

3 years ago

Which apparatus is used to measure mass of a bread

Harrizon [31]

Explanation:

a triple beam balance can measure the mass of one slice of bread

3 0

3 years ago

What factors could enhance memory and kept constant? and why

artcher [175]

To help make sure information goes from short-term memory to long-term memory, you can use memory-enhancing strategies. One strategy is rehearsal, or the conscious repetition of information to be remembered. Think about how you learned your multiplication tables as a child.

Proven ways to protect memory include following a healthy diet, exercising regularly, not smoking, and keeping blood pressure, cholesterol, and blood sugar in check. Living a mentally active life is important, too. Just as muscles grow stronger with use, mental exercise helps keep mental skills and memory in tone.

According to one study, mental stimulation like reading can help protect memory and thinking skills, especially as you age. The authors even suggest that reading every day can slow down the late-life cognitive decline. ... The act of reading helps to heighten overall brain function and increase memory.

Let's take a deeper dive into evidence-based exercises that offer the best brain-boosting benefits.

Have fun with a jigsaw puzzle. ...

Try your hand at cards. ...

Build your vocabulary. ...

Dance your heart out. ...

Use all your senses. ...

Learn a new skill. ...

Teach a new skill to someone else. ...

Listen to or play music.

8 0

3 years ago