Answer:
ocean covers 71 percent of the earth
Answer:
60 km
Explanation:
For an object (or a person, such as in this case) moving at constant speed, the speed is equal to the ratio between the distance travelled and the time taken:
where
v is the speed
d is the distance
t is the time taken
In this case, we have:
v = 120 km/h is the speed
t = 30 min = 0.5 h is the time taken
Therefore, we can rearrange the equation to find the total distance travelled:
A) 500 calories
B)5000 joules
C) 5 kilocalories
Answer is C
Kinetic energy = (1/2) (mass) (speed)²
Before slowing down, the car's speed is 25 m/s,
and its kinetic energy is ...
(1/2) (1,500 kg) (25 m/s)²
= (1/2) (1,500 kg) (625 m²/s²)
= 468,750 joules .
After slowing down, the car's speed is 15 m/s,
and its kinetic energy is ...
(1/2) (1,500 kg) (15 m/s)²
= (1/2) (1,500 kg) (225 m²/s²)
= 168,750 joules.
The car lost (468,750 - 168,750) = 300,000 joules of K.E.
The law of Conservation of Energy says:
That 300,000 joules had to go somewhere.
If it's a standard, gas-powered car, then the kinetic energy got
put into the brakes. The energy turned into heat, and the heat
was carried off in the air.
If it's a more modern electric or hybrid car, then the kinetic energy
spun the wheel motors, turning them temporarily into electrical
generators. The generators converted the kinetic energy into
electrical energy, which got put back into the car's batteries, and
could be used again. That's why electric cars use less gas.
Answer:
12. you measure mass with a balnece. such as a triple balence beam or an electronic balance.
i dont know 11 sorry
