Explanation:
d= 80km = 8000m
t = 45 min = 45/60 h
= 0.75 h
V= ?
we know that,
V = d /t
or,V= 80 km / 0.75 h
- or, V= 106.67 km/hr
or,V= 106.67×1000m / 3600 s
2. or, V= 29.63 m/s
Answer:
a. The total momentum of the trolleys which are at rest before the separation is zero
b. The total momentum of the trolleys after separation is zero
c. The momentum of the 2 kg trolley after separation is 12 kg·m/s
d. The momentum of the 3 kg trolley is -12 kg·m/s
e. The velocity of the 3 kg trolley = -4 m/s
Explanation:
a. The total momentum of the trolleys which are at rest before the separation is zero
b. By the principle of the conservation of linear momentum, the total momentum of the trolleys after separation = The total momentum of the trolleys before separation = 0
c. The momentum of the 2 kg trolley after separation = Mass × Velocity = 2 kg × 6 m/s = 12 kg·m/s
d. Given that the total momentum of the trolleys after separation is zero, the momentum of the 3 kg trolley is equal and opposite to the momentum of the 2 kg trolley = -12 kg·m/s
e. The momentum of the 3 kg trolley = Mass of the 3 kg Trolley × Velocity of the 3 kg trolley
∴ The momentum of the 3 kg trolley = 3 kg × Velocity of the 3 kg trolley = -12 kg·m/s
The velocity of the 3 kg trolley = -12 kg·m/s/(3 kg) = -4 m/s
<h3><u>Answer;</u></h3>
the one with the highest specific heat
<h3><u>Explanation;</u></h3>
- The specific heat is the amount of heat per unit mass required to raise the temperature by one degree Celsius.
- The specific heat of water is 1 calorie/gram °C or 4.186 joule/gram °C which is higher than any other common substance.
- <em><u>A metal with the highest specific heat will cause the greatest increase in temperature of water in a calorimeter because the metal would hold more heat, and then transfer the greater quantity of heat to the water.</u></em>
Answer:
The specific heat of liquid water is about 4184 J/kg at 20 °C.
So, <u>Correct choice</u> - [C] 4186 J / kg ° C
