A 1200-kg car initially at rest undergoes constant acceleration for 8.8 s, reaching a speed of 10 m/ s. It then collides with a
1 answer:
Answer:
The final kinetic energy of the two-car system is 60,000 J.
Explanation:
Given;
mass of the car, m = 1200 kg
time of motion, t = 8.8 s
final velocity of the car, v = 10 m/s
Apply the principle of conservation of kinetic energy; the initial kinetic energy is equal final kinetic energy.
Therefore, the final kinetic energy of the two-car system is 60,000 J.
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Answer:
the ball travelled approximately 60 m towards north before stopping
Explanation:
Given the data in the question;
First course : = 0.75 m/s²,
= 20 m,
= 10 m/s
now, form the third equation of motion;
v² = u² + 2as
we substitute
² = (10)² + (2 × 0.75 × 20)
² = 100 + 30
² = 130
= √130
= 11.4 m/s
for the Second Course:
= 11.4 m/s,
= -1.15 m/s²,
= 0
Also, form the third equation of motion;
v² = u² + 2as
we substitute
0² = (11.4)² + (2 × (-1.15) × )
0 = 129.96 - 2.3
2.3 = 129.96
= 129.96 / 2.3
= 56.5 m
so;
|d| = √( ² +
² )
we substitute
|d| = √( (20)² + (56.5)² )
|d| = √( 400 + 3192.25 )
|d| = √( 3592.25 )
|d| = 59.9 m ≈ 60 m
Therefore, the ball travelled approximately 60 m towards north before stopping
Answer:
a) The swimmer should travel perpendicular to the bank to minimize the spent in getting to the other side.
b) 133.33 m
c) 53.13°
d) 106.67 m
Explanation:
a) The swimmer should travel perpendicular to the bank to minimize the spent in getting to the other side.
b) velocity = distance * time
Let the velocity of the swimmer be = 1.5 m/s
The separation of the two sides of the river, d = 80 m
The time taken by the swimmer to get to the other end of the river bank,
t = 80/1.5
t = 53.33 s
The swimmer will be carried downstream by the river through a distance, s
Let the velocity of the river be = 2.5 m/s
S = 53.33 * 2.5
S = 133.33 m
c) To minimize the distance traveled by the swimmer, his resultant velocity must be perpendicular to the velocity of the swimmer relative to water
That is ,
d) Downstream velocity of the swimmer,
The vertical displacement is given by,
80 = 1.2 t
t = 80/1.2
t = 66.67 s
the horizontal speed,
The downstream horizontal distance of the swimmer,
x = 1.6 * 66.67
x = 106.67 m