Stone needs 1350 J of energy to crack down. A bullet of 120 gm is fired on

Will give 45 points to who ever solves this

Lubov Fominskaja [6]

Answer:

1. 230 kg...

W = m * g

W= 230 kg * 9.81 m/s^2

W= 2256,3 N

m= 230kg , W = 2256,3 N , g= 9.81 m/s^2

2. 887 N

W= m * g

887 N = m * 9.81 m/s^2

m= 90,42 kg

m= 90,42 kg, W = 887 N , g= 9.81 m/s^2

3. 420 kg

W= m * a

w= 420 kg * 9.81 m/s^2

w= 4120,2 N

m= 420 kg , W = 4120,2 N , g= 9.81 m/s^2

4. Determine the gravity on Pluto where a 15 kg object weighs 55.5N.

w = m * g

55.5 N = 15 kg * g

a= 3,7 m/s^2

m = 15 kg , W= 55.5 N , g= 3,7 m/s^2

7 0

2 years ago

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When a massive star greater than 8 solar masses has its core filled with iron, the core can no longer continue fusion, and it be

Musya8 [376]

I know if honest at this point right

4 0

3 years ago

A police officer is parked by the side of the road, when a speeding car travelling at 50 mi/hrpasses. The police car immediately

Blababa [14]

Answer:

a) time taken to catch up with speeding car is 12.25 secs

b) the police car will travel 273.8 m to catch up with the speeding car

Explanation:

Given that;

speed of car $V_{c}$ = 50 mi/hr = 22.352 m/s

acceleration of police car = 10 mi/hr = 4.47 m/s²

$V_{f}$ = 70 mi/hr = 31.29 m/s

Now time taken to reach maximum speed is t₁

so

$V_{f}$ = $V_{i}$ + at₁

we substitute

31.29 = 0 + 4.47t₁

t₁ = 31.29 / 4.47

t₁ = 7 sec

now

d₁ = 0 + 1/2 × at₁²

d₁ = 0 + 1/2 × 0 + 4.47×(7)²

d₁ = 109.5 m

so distance travelled by the speeding car in time t₁ will be

$d_{c}$ = $V_{c}$ × t₁

we substitute

$d_{c}$ = 22.352 × 7

$d_{c}$ = 156.46 m

now distance between polive car and speeding car

Δd = $d_{c}$ - d₁

Δd = 156.46 - 109.5

Δd = 46.96 m

time taken to cover Δd will be

t₂ = Δd / ( $V_{f}$ - $V_{c}$ )

t₂ = 46.96 / ( 31.29 - 22.352 )

t₂ = 46.96 / 8.938

t₂ = 5.25 sec

distance travelled by the police in time t₂ will be

d₂ = $V_{f}$ × t₂

d₂ = 31.29 × 5.25

d₂ = 164.3 m

a) How long will it take before the officer catches up to the speeding car;

time taken to catch up with speeding car;

t = t₁ + t₂

t = 7 + 5.25

t = 12.25 secs

Therefore, time taken to catch up with speeding car is 12.25 secs

b) how far will it have travelled in order to do so;

distance = d₁ + d₂

distance = 109.5 + 164.3

distance = 273.8 m

Therefore, the police car will travel 273.8 m to catch up with the speeding car

6 0

3 years ago

Diego is trying to lift a piano to the second floor of his house. Diego uses a pulley system and gives a big lift to the piano.T

Mila [183]

Answer:

Correct Answer is positive force → balanced force → negative force

Explanation:

When Diego gives a big lift to the piano with the help of pulley system that time, initially piano moves upward so positive force acts on it.

Later, Piano stops, in this condition balanced force act on it since force applied by Diego is balanced by gravitational force of earth.

After some time piano starts falling in this condition negative force will act on the piano. In this condition, gravitational force will acts on piano in downward direction.

3 0

4 years ago

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Se lanza una pelota de hule elástica de masa mA con una velocidad VAi contra la puerta trasera de un camión muy pesado de masa m

miv72 [106K]

Answer:

$v_{A}=v_{Ai}$

Explanation:

The total momentum of the system must conserve by the law of momentum conservation.

$p_b=p_a\\\\m_Av_{Ai}+m_Bv_{Bi}=m_Av_{A}+m_Bv_{B}$ ( 1 )

If you consider the shock between the ball and the truck as totally elastic, and also if the truck is much more massive than the ball, you can assume that the truck does not move when the ball hits it.

Then the truck is always at rest

Hence, you have in the expression ( 1 ):

$m_Av_{Ai}+0=m_Av_{A}+0\\\\v_{Ai}=v_{A}$

3 0

3 years ago