Answer:
Explanation:
Acceleration is the change in velocity with respect to time.
Acceleration = change in velocity/Time
Acceleration = final velocity - initial velocity/Time
Given initial velocity = 10m/s
Final velocity = 20m/s
Time taken = 4s
Acceleration = 20-10/4
Acceleration = 10/4
Acceleration =2.5m/s²
For the second part of the question:
Given parameters
initial velocity = 15m/s
acceleration = -3m/s²
time = 4seconds
a = v-u/t
-3 = v-15/4
cross multiply
-12 = v-15
add 15 from both sides
-12+15 = v-15+15
3 = v
<em>Hence the final velocity of the car is 3m/s</em>
Answer:
110.7 J
Explanation:
Hooke's law is represented by the formula:
F = ke where F is the force in Newton, K is force constant and e is extension in m
work done = 1/2ke² = 1/2 K ( e² - e₀²) and e₀ is the extension at relaxed length
e₀ =0
work done = 0.5 × 82N/m × (2.70 m)² = 110.7 J
Answer:
First answer.
Explanation:
There may be a 5N force, but if the frictional force also equals 5N, than they cancel eachother out, resulting in the brick still staying still, as it is resting on a (perfectly) level surface, but any amount of force would make the brick move.