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.
Answer:
the final speed of the rain is 541 m/s.
Explanation:
Given;
acceleration due to gravity, g = 9.81 m/s²
height of fall of the rain, h = 9,000 m
time of the rain fall, t = 1.5 minutes = 90 s
Determine the initial velocity of the rain, as follows;
The final speed of the rain is calculated as;
Therefore, the final speed of the rain is 541 m/s.
Answer:
The average velocity is 8 unit per sec
Explanation:
Given as :
The Distance x = 20 - 4t² unit
Change in time Δt = ( 2 - 0 ) s = 2 s
Let the velocity = V unit/s
∴ V =
Or, V = - 8t unit/s
Now velocity at t = 0
V1 = - 8 × 0 = 0 unit/s
And velocity at t = 2 sec
V2 = - 8 × 2 = - 16
So, Average velocity = =
= -8
Or, = 8 unit/sec
Hence The average velocity is 8 unit per sec Answer