All categories

3 years ago

A car moving with constant acceleration covers the distance between two points 180 m apart in

Physics

1 answer:

patriot [66]3 years ago

6 0

distance = 180m

time = 6 secs

velocity = 45m/s

s= ut+ 1/2at²

2s=2ut+at²

2s-2ut= at²

2(180)-2(25)(6) =a(6)²

60=36a

1.66666 m/s² = a

You might be interested in

is the science that manages the database, digital tools, and software used by both medicine and forensic science to store and an

Ne4ueva [31]

Explanation :

Bioinformatics is the science that manages the database, digital tools and software used by both medicine and forensic science to store and analyze DNA.

It involves the use of computers to collect all the data and organize data. It also develops methods and computational tools for understanding biological data.

It helps in tracing the evolution of organism using DNA and builds a computational model.

8 0

3 years ago

A porter can carry 40 bricks of 10 N load of each. He can carry up to 75m in 40 sec, calculate his power.

alexira [117]

Answer:

750W

Explanation:

40×10= 400N

work done= force × distance

=400 × 75

=30000 J

Power= work done/ time

= 30000 ÷ 40

= 750 W

4 0

1 year ago

Which scenario presents a possible environmental impact due hydrogen fuel cells?

Mekhanik [1.2K]

The scenario that presents a possible environmental impact due to hydrogen fuel cells is that, the electricity used to supply the fuel cells with Hydrogen is produced using fossil fuels.

The question is incomplete, but these should have been the options;

a.) The fuel cells are used to power internal combustion engines rather than electric motors.

b.) The electricity used to supply the fuel cells with hydrogen is produced using fossil fuels.

c.) The combined exhaust emissions from fleets of buses equipped with fuel cells generates smog.

d.) None of these are correct.

The answer therefore is option B. The Hydrogen fuel cell is a device that uses Hydrogen as an energy source to power machines and to generate heat and electricity. It is a green energy alternative to fossil fuels as unlike fossil fuels, it doesn't produce green house gases and is non-toxic. Also, unlike other clean sources of energy like wind and water, it doesn't require a large area of land to be produced.

Hydrogen fuel cells work by combining hydrogen and oxygen atoms. The resulting energy produced is converted to electrical energy which can be used to power electrical motors, while the by-product, water is non-toxic, renewable and doesn't create smog.

However, to produce the hydrogen used in the cells, high amount of energy is required in order to separate hydrogen from oxygen. To accomplish this, fossil fuels such as coal, natural gas and oil are used, releasing harmful emissions which creates a negative environmental impact. This makes the answer to the above question option B. A better alternative though, is to use other renewable energy sources like wind or solar.

To learn more about the benefits of Hydrogen fuel cells, visit;

brainly.com/question/6501095

#SPJ4

8 0

2 years ago

A parachutist falls 50.0 m without friction. When the parachute opens, he slows down at a rate of 67 m/s*2. If he reaches the gr

KIM [24]

Answer:

3.49 seconds

3.75 seconds

-43200 ft/s²

Explanation:

t = Time taken

u = Initial velocity

v = Final velocity

s = Displacement

a = Acceleration

$s=ut+\frac{1}{2}at^2\\\Rightarrow 50=0t+\frac{1}{2}\times 9.81\times t^2\\\Rightarrow t=\sqrt{\frac{50\times 2}{9.81}}\\\Rightarrow t=3.19\ s$

Time the parachutist falls without friction is 3.19 seconds

$v^2-u^2=2as\\\Rightarrow v=\sqrt{2as+u^2}\\\Rightarrow v=\sqrt{2\times 9.81\times 50+0^2}\\\Rightarrow v=31.32\ m/s$

Speed of the parachutist when he opens the parachute 31.32 m/s. Now, this will be considered as the initial velocity

$v=u+at\\\Rightarrow 11=31.32+9.81t\\\Rightarrow t=\frac{11-31.32}{-67}=0.3\ s$

So, time the parachutist stayed in the air was 3.19+0.3 = 3.49 seconds

$s=ut+\frac{1}{2}at^2\\\Rightarrow \frac{s}{2}=0t+\frac{1}{2}\times a\times t^2\\\Rightarrow \frac{s}{2}=\frac{1}{2}at^2$

$s=ut+\frac{1}{2}at^2\\\Rightarrow \frac{s}{2}=u1.1+\frac{1}{2}\times a\times 1.1^2$

Now the initial velocity of the last half height will be the final velocity of the first half height.

$v=u+at\\\Rightarrow v=at$

Since the height are equal

$\frac{1}{2}at^2=u1.1+\frac{1}{2}\times a\times 1.1^2\\\Rightarrow \frac{1}{2}at^2=at1.1+\frac{1}{2}\times a\times 1.1^2\\\Rightarrow 0.5t^2-1.1t-0.605=0\\\Rightarrow 500t^2-1100t-605=0$

$t=\frac{11\left(1+\sqrt{2}\right)}{10},\:t=\frac{11\left(1-\sqrt{2}\right)}{10}\\\Rightarrow t=2.65, -0.45$

Time taken to fall the first half is 2.65 seconds

Total time taken to fall is 2.65+1.1 = 3.75 seconds.

When an object is thrown with a velocity upwards then the velocity of the object at the point to where it was thrown becomes equal to the initial velocity.

$v^2-u^2=2as\\\Rightarrow a=\frac{v^2-u^2}{2s}\\\Rightarrow a=\frac{0^2-240^2}{2\times \frac{8}{12}}\\\Rightarrow a=-43200\ ft/s^2$

Magnitude of acceleration is -43200 ft/s²

5 0

3 years ago

Which of the following is evidence that supports the idea of uniformitarianism?

Inga [223]

D. rates of soil erosion are much lower during droughts that last several years

5 0

4 years ago