Answer:
Explanation:
Q = m c Δt
heat withdrawn to lower temperature by 40° C
Q = 1 X 1000 X 40 = 40,000 calories.
Q = mL
heat withdrawn to freeze water at 0°C to ice
= 1 x 80000 = 80,000 calories
total heat to be withdrawn = 120,000 calories. = 120,000 x 4.2 = 504 ,000 Joules.
Answer:
The force needed to slow down the car is, F = 67.5 N
Explanation:
Given data,
The mass of the car, m = 15 kg
The initial velocity of the car, V = 60 m/s
The final velocity of the car, v = 15 m/s
The time period of deceleration, t = 10 s
The difference in the momentum of the car is,
mV - mv = 15(60 - 15)
= 675 kg m/s
The rate of change in momentum of the car gives the force acting on it.
F = (mV - mu) / t
Substituting the values,
F = 675 / 10
= 67.5 N
Hence, the force needed to slow down the car is, F = 67.5 N
Answer:
Car 1 and Car 2 have the same momentum!
Explanation:
Using the formula of momentum (P=m*v), we get for each car:
Car 1: 5kg*2.2m/s = 11kg*m/s
Car 2: 5.5kg*2m/s = 11kg*m/s
Car 3: 6kg*1.35m/s = 8.1kg*m/s
Car 4: 6.5kg*1.9m/s = 12.35kg*m/s
Car 5: 7kg*1.25m/s = 8.75kg*m/s
The pressure in the balloon increases.
