All categories

3 years ago

I NEED AN ANSWER ASAP PLEASE!!

Physics

1 answer:

alina1380 [7]3 years ago

7 0

Answer:

The last one, I believe :)

Explanation:

You might be interested in

A man whose mass is 69 kg and a woman whose mass is 52 kg sit at opposite ends of a canoe 5 m long, whose mass is 20 kg. Suppose

dusya [7]

Answer:

the canoe moved 1.2234 m in the water

Explanation:

Given that;

A man whose mass = 69 kg

A woman whose mass = 52 kg

at opposite ends of a canoe 5 m long, whose mass is 20 kg

now let;

x1 = position of the man

x2 = position of canoe

x3 = position of the woman

Now,

Centre of mass = [m1x1 + m2x2 + m3x3] / m1 + m2 + m3

= ( 69×0 ) + ( 52×5) + ( 20× 5/2) / 69 + 52 + 20

= (0 + 260 + 50 ) / ( 141 )

= 310 / 141

= 2.19858 m

Centre of mass is 2.19858 m

Now, New center of mass will be;

52 × 2.5 / ( 69 + 52 + 20 )

= 130 / 141

= 0.9219858 m { away from the man }

To get how far, the canoe moved;

⇒ 2.5 + 0.9219858 - 2.19858

= 1.2234 m

Therefore, the canoe moved 1.2234 m in the water

5 0

3 years ago

What is the difference between speed and velocity?

avanturin [10]

Answer:

speed is the rate of change in distance thus it is scalar physical quantity

while velocity is the rate of change in displacement thus it is a vector physical quantity

Explanation:

vector physical quantity: is a quantity that requires both magnitude and direction to identify

scalar quantity: requires only magnitude to identify.

6 0

3 years ago

In which type of wave do air particles move together or apart parallel to the direction of the wave?

Kitty [74]

C. Sound waves is the answer =P

7 0

4 years ago

Calculate the height of a cliff if it takes 2.35 s for a rock to hit the ground when it is thrown straight up from the cliff wit

pantera1 [17]

Answer:

height of a cliff is 45.86 m

Explanation:

u=8 m/s

t=2.35 s

the height of the cliff is

$S=ut+\frac{1}{2} at^2\\S=8\times2.35+\frac{1}{2} \times 9.8 \times 2.35^2\\S=45.86 m$

7 0

3 years ago

Suppose you wanted to hold up an electron against the force of gravity by the attraction of a fixed proton some distance above i

SCORPION-xisa [38]

Answer:

The value is $r = 5.077 \ m$

Explanation:

From the question we are told that

The Coulomb constant is $k = 9.0 *10^{9} \ N\cdot m^2 /C^2$

The charge on the electron/proton is $e = 1.6*10^{-19} \ C$

The mass of proton $m_{proton} = 1.67*10^{-27} \ kg$

The mass of electron is $m_{electron } = 9.11 *10^{-31} \ kg$

Generally for the electron to be held up by the force gravity

Then

Electric force on the electron = The gravitational Force

i.e

$m_{electron} * g = \frac{ k * e^2 }{r^2 }$

$\frac{9*10^9 * (1.60 *10^{-19})^2 }{r^2 } = 9.11 *10^{-31 } * 9.81$

$r = \sqrt{25.78}$

$r = 5.077 \ m$

7 0

3 years ago