Answer:
Explanation:
a ) Let the distance required in former case be d₁ .
initial velocity u = 30 m /s , final velocity v =0 , deceleration a = 7.00 m /s²
v² = u² - 2 a s
0 = 30² - 2 x 7 x d₁
d₁ = 64.28 m
b) initial velocity u = 30 m /s , final velocity v =0 , deceleration a = 5.00 m /s²
v² = u² - 2 a s
0 = 30² - 2 x 5 x d₂
d₂ = 90 m
c)
t = .5 s
s₁ = ut - .5 at²
= 30 x .5 - .5 x 7 x .5²
= 15 - .875
= 14.125 m
t = .5 s
s₂ = ut - .5 at²
= 30 x .5 - .5 x 5 x .5²
= 15 - .625
= 14.375 m
It is difficult for astronomers to find object like planets and asteroids because it takes a lot of time to verify the objects locations and what surrounds a certain object in order to prove and be precise of its location
The heat released by the water when it cools down by a temperature difference

is

where
m=432 g is the mass of the water

is the specific heat capacity of water

is the decrease of temperature of the water
Plugging the numbers into the equation, we find

and this is the amount of heat released by the water.
Answer:
1196.02 °C
Explanation:
If the kinetic energy is converted into heat,
then,
Kinetic energy of the copper = heat energy of the copper
1/2m(v²) = cm(t₂-t₁)
where m = mass of copper, v = velocity of copper, c = specific heat capacity of copper, t₂ = final temperature of copper, t₁ = initial temperature of copper.
Since the mass of copper remains the same,
1/2v² = c(t₂-t₁)
make t₂ the subject of the equation
t₂ = 1/2(v²/c)+t₁..................... Equation 1
Given: v = 950 m/s, c = 387 J/kg°C, t₁ 30 °C
Substitute into equation 1
t₂ = 1/2(950²/387)+30
t₂ = 1196.02 °C
Hence the temperature the bullet reach before it was stopped = 1196.02 °C