Answer:
(a) 2 (b) 4 (c) 4
Explanation:
Significant figures : The figures in a number which express the value -the magnitude of a quantity to a specific degree of accuracy is known as significant digits.
Rules for significant figures:
- Digits from 1 to 9 are always significant and have infinite number of significant figures.
- All non-zero numbers are always significant. For example: 654, 6.54 and 65.4 all have three significant figures.
- All zero’s between integers are always significant. For example: 5005, 5.005 and 50.05 all have four significant figures.
- All zero’s preceding the first integers are never significant. For example: 0.0078 has two significant figures.
- All zero’s after the decimal point are always significant. For example: 4.500, 45.00 and 450.0 all have four significant figures.
- All zeroes used solely for spacing the decimal point are not significant. For example : 8000 has one significant figure.
As per question,
0.000054 has 2 significant figures.
3.001 x 10⁵ has 4 significant figures.
5.600 has 4 significant figures.
Answer:
0.82 m
Explanation:
The ball is in free fall - uniform accelerated motion with constant acceleration downward,
(acceleration of gravity). So we can use the following suvat equation to solve the problem:

where
v is the final velocity
u = 4 m/s is the initial velocity
a is the acceleration
s is the displacement
At the maximum displacement, v = 0 (the velocity becomes zero). Substituting and solving for s, we find:

Answer:
A) 6N
Explanation:
the weight of the astronaut on earth can be calculated with the formula
Weight = mass * gravity of earth
Since the gravitational force is one-hundredth of Earth, the formula should be
Weight = mass * (gravity of earth / 100)
Weight = (mass * gravity of earth) / 100
Since you already know the weight, you only need to divide by 100
Weight = (mass * gravity of earth) / 100
Weight = 600N / 100
Weight = 6N
Answer:
0.09 N
Explanation:
We are given that
Radius of disk,r=6 cm=
1 m=100 cm
B=1 T
Current,I=3 A
We have to find the frictional force at the rim between the stationary electrical contact and the rotating rim.





Torque due to friction

Where friction force=F


Substitute the values


Explanation:
The given data is as follows.
k = 130 N/m,
= 17 cm = 0.17 m (as 1 m = 100 cm)
mass (m) = 2.8 kg
When the spring is compressed then energy stored in it is as follows.
Energy = 
Now, spring energy gets converted into kinetic energy when the box is launched.
So,
= 
= 

= 1.34
v = 1.15 m/sec
Now,
Frictional force = 
= 
= 4.116 N
Also, Kinetic energy = work done by friction
1.8515 =
d = 0.449 m
Thus, we can conclude that the box slides 0.449 m across the rough surface before stopping.