Answer:
Friction is a force that holds back the movement of a sliding object.
Explanation:
The two types of friction: Static friction and Kinetic friction. Static friction operates between two surfaces that aren't moving relative to each other, while kinetic friction acts between objects in motion.
Given values:
Mass of the steel ball, m = 100 g = 0.1 kg
Height of the steel ball, h1 = 1.8 m
Rebound height, h2 = 1.25 m
a. PE= mgh
0.1 x 9.8 x 1.8 =
1.764 Joules
b. KE = PE ->
1.764 Joules
c. KE= 1/2 mv square
so v = square root 2ke/m
square root 2 x 1.764/ 0.1
= 5.93 m/s
d. KE=PE=mgh square
0.1 x 9.8 x 1.21 =
1.186 joules
velocity of rebond is square root 2x 1.186/ 0.1 = 4.87 m/s
Very simple,Its all about calculating distance using the formula:
D = V x T
where,
V is the speed or velocity
D is distance
T is the time
In the given problem,there are two parts.
Lets do the calculations for both parts separately:
Part 1) Before the rain
Time = 130/95
= 1.37 hours <span> </span>
<span>Time taken after the rain = Total time - time taken before the rain </span>
<span> = 3.34 hours - 1.37 hours
= 1.97 hours </span>
<span>Distance covered after the rain = 1.97 hours x 65 km/h
= 128 km</span>
Hence,
<span>a) The total distance covered = 130 + 128
= 258 km
</span><span>b) Average speed = Total distance/Total time
= 260/3.34
= 78 km/h </span>
