Given: The number = 0.0069 that has to be expressed in scientific notation
Concept: When we express any number in scientific notation then we shall consider two points.
(i) If we shift the decimal point from left to right after first (non-zero) digit then we count the number of shifted place of decimal and write them in terms of the negative power of 10. For example, 0.004789 = 4.789 ×10⁻³
(ii) If we shift the decimal point from right to left after first (non-zero) digit from the left end then we count the number of shifted place and write then in terms of the positive power of 10. For example, 4789.24 = 4.78924 ×10⁺³ = 4.78924 ×10³ Now, we shall convert the given number 0.0069 in scientific notation
0.0069 = 6.9 ×10⁻³ because we have shifted the decimal from left to right for three places that is after digit 6.
Hence, the last option 6.9 ×10⁻³ will be the correct option.
Answer:
ω₂=1.20
Explanation:
Given that
mass of the turn table ,M= 15 kg
mass of the ice ,m= 9 kg
radius ,r= 25 cm
Initial angular speed ,ω₁ = 0.75 rad/s
Initial mass moment of inertia
Final mass moment of inertia
Lets take final speed of the turn table after ice evaporated =ω₂ rad/s
Now by conservation angular momentum
I₁ ω₁ =ω₂ I₂
ω₂=1.20
Answer:
16250 kgm/s due south
Explanation:
Applying,
M = mv................. Equation 1
Where M = momentum, m = mass, v = velocity.
From the car,
Given: m = 1000 kg, v = 6.5 m/s
Substitute these values into equation 1
M = 1000(6.5)
M = 6500 kgm/s
For the truck,
Given: m = 3500 kg, v = 6.5 m/s
Substitute these values into equation 1
M' = 3500(6.5)
M' = 22750 kgm/s.
Assuming South to be negative direction,
From the question,
Total momentum of the two vehicles = (6500-22750)
Total momentum of the two vehicles = -16250 kgm/s
Hence the total momentum of the two vehicles is 16250 kgm/s due south
The force the horse and the rider exerts on the wall is equal to the weight combined acting in the opposite direction:
<h3>Force</h3>
Given Data
- mass of horse and rider = 575kg
- Force acting on wall = ??
When a body of mass rests on a surface, it exerts a force equal to the weight of the mass but opposite in direct on the mass/object
hence the force is computed as
Force = mass * acceleration
Force = 575 * 9.81
Force = 5640.75N
Learn more about force here:
brainly.com/question/12970081
<h2>The distance between students is 2.46 m</h2>
Explanation:
The force of attraction due to Newton's gravitation law is
F = 
Here G is the gravitational constant
m₁ is the mass of one student
m₂ is the mass of second student .
and r is the distance between them
Thus r = 
If we substitute the values in the above equation
r = 
= 2.46 m
