Answer:
He needs 1.53 seconds to stop the car.
Explanation:
Let the mass of the car is 1500 kg
Speed of the car, v = 20.5 m/s
He will not push the car with a force greater than, 
The impulse delivered to the object is given by the change in momentum as :

So, he needs 1.53 seconds to stop the car. Hence, this is the required solution.
259200 seconds in 3 days and 136800 seconds in 38 hours
Answer:
8000 kg/cm^3
Explanation:
The density formula is P = M/V
Density = P = ? expressed in kg/m^3
M = mass = 40,000 kg
V = volume = 5 m^3
P = 40,000/5
P = 8000 kg/m^3
Answer:
i believe he threw the ball up at about 18 mph
Explanation: