Answer:
The time it will take for the car to reach a velocity of 28 m/s is 7 seconds
Explanation:
The parameters of the car are;
The acceleration of the car, a = 4 m/s²
The final velocity of the car, v = 28 m/s
The initial velocity of the car, u = 0 m/s (The car starts from rest)
The kinematic equation that can be used for finding (the time) how long it will take for the car to reach a velocity of 28 m/s is given as follows;
v = u + a·t
Where;
v = The final velocity of the car, v = 28 m/s
u = The initial velocity of the car = 0 m/s
a = The acceleration of the car = 4 m/s²
t = =The time it will take for the car to reach a velocity of 28 m/s
Therefore, we get;
t = (v - u)/a
t = (28 m/s - 0 m/s)/(4 m/s²) = 7 s
The time it will take for the car to reach a velocity of 28 m/s, t = 7 seconds.
Answer:
The initial velocity of the snowball was 22.21 m/s
Explanation:
Since the collision is inelastic, only momentum is conserved. And since the snowball and the box move together after the collision, they have the same final velocity.
Let 
be the mass of the ball, and 
be its initial velocity; let 
be the mass of the box, and 
be its velocity; let 
be the final velocity after the collision, then according to the law of conservation of momentum:
.
From this we solve for , the initial velocity of the snowball:
now we plug in the numerical values 
, 
, 
, and 
to get:
The initial velocity of the snowball is 22.21 m/s.
<em>P.S: we did not take vectors into account because everything is moving in one direction—towards the west.</em>
