<u>Answer:</u>
<em>The average speed of the car is 66.9 km/h</em>
<u>Explanation:</u>
Here distance covered with the speed <em>57 km/h=7 km </em>
distance covered with the speed of <em>81 km/h=7 km</em>
<em>Average speed is equal to the ratio of total distance to the total time.
</em>
<em>total distance= 7 + 7= 14 km </em>
<em>
</em>
<em>time taken to cover the first 7 km= 7/57 h </em>
<em>time taken to cover the second part of the journey = 7/81 h
</em>
<em>average speed = 
</em>
<u><em>Shortcut:
</em></u>
<em>When equal distances are covered with different speeds average speed=2 ab/(a+b) where a and b are the variable speeds in the phases.
</em>
Answer:
s = 589.3 m
Explanation:
Let the truck and car meet at a distance = s m
The truck is moving at constant velocity = v
so s= v * t ---------- (1)
car:
Vi = 0 m/s
a = 3.9 m/s²
s = Vi* t + 1/2 a t²
s= 0 * t + 1/2 a t²
s = 1/2 a t² ----------- (2)
compare equation (1) and equation (2)
s= v * t = 1/2 a t²
⇒ v * t = 1/2 a t²
⇒ t = 2 * v/ a
⇒ t = (2 * 33.9 )/ 3.9
⇒ t = 17. 38 s
Now
from equation (1)
s= v * t
s= 33.9 * 17.38
⇒ s = 589.3 m
Current will be
now just pluf in the values and Voila..
Answer:
Simple harmonic motion is the movement of a body or an object to and from an equilibrium position. In a simple harmonic motion, the maximum displacement (also called the amplitude) on one side of the equilibrium position is equal to the maximum displacement.
The force acting on an object must satisfy Hooke's law for the object to undergo simple harmonic motion. The law states that the force must be directed always towards the equilibrium position and also directly proportional to the distance from this position.
Answer:
4 seconds
Explanation:
Given:
v₀ = 20 m/s
v = 0 m/s
a = -5 m/s²
Find: t
v = at + v₀
0 m/s = (-5 m/s²) t + 20 m/s
t = 4 s
