solve the following
Answers
Step-by-step explanation:
10.
Given that
Total distance covered by the wheel of the truck = 78.5 km
Diameter of the wheel = 1 m
Radius = Diameter/2
=> Radius = 1/2 m
Total distance covered in one revolution = Circumference of the wheel
We know that
Circumference of a circle = 2πr units
=> 2×3.14 × 1/2 m
=> 3.14 m
Number of revolutions
= Total distance / Distance covered in one revolution
=> 78.5 km / 3.14 m
We know that
1 km = 1000 m
=> 78.5×1000/3.14
=> 78500/3.14
=> 78500/(314/100)
=> 7850000/314
=> 25000
Total number of revolutions = 25000
11.
Given that
The length of the hour hand of a clock = 4.9 cm
=> Radius of the circle = 4.9 cm
Total distance covered by the hour hand in one revolution = Circumference of the circle
=2πr units
= 2(3.14)×4.9 cm
= 30.772 cm
= 30.8 cm
The hour hand moves two times from a point
The distance covered by the hour hand in a day
= 30.8×2
= 61.6 cm
The total distance travelled by the tip of the hour hand in a week
= 61.6×7
= 431.2cm
The total distance travelled by the tip of the hour hand in a week = 431.2 cm
12.
Given that
Measurements of the wooden strip = 80 cm and 50 cm
Total wooden strip is required to frame a photograph is the perimeter of the rectangle
We know that
Perimeter of a rectangle = 2(l+b) units
Perimeter of the photo frame
=> P = 2(80+50) cm
=> P = 2(130) cm
=> P = 260 cm
We know that
1 m = 100 cm
=> 1 cm = 1/100 m
P = 260/100 = 2.60 m
The cost of the 1 m of wooden strip = Rs. 10
Total cost of the wooden strip is required to frame the photograph
= 2.60× 10
= 2.6×10
= Rs. 26
Total cost of the wooden strip is Rs. 26
Answer:
The ionosphere is ionized by solar radiation. It plays an important role in atmospheric electricity and forms the inner edge of the magnetosphere. It has practical importance because, among other functions, it influences radio propagation to distant places on the Earth.
Step-by-step explanation: