Answer:
8.4 m/s
Explanation:
The toy completes 10 circle in 30 seconds. So its frequency of revolution is

The periof of revolution is the reciprocal of the frequency, so

The radius of the circular path is
r = 4.0 m
So the total distance covered by the toy in one circle is the length of the circumference:

And so the average speed is

According to the second law of thermodynamics,
the answer is
<span>4. The entropy of the universe is increasing. </span>
Answer:
linear density of the string = 4.46 × 10⁻⁴ kg/m
Explanation:
given,
mass of the string = 31.2 g
length of string = 0.7 m
linear density of the string = 
linear density of the string = 
linear density of the string = 44.57 × 10⁻³ kg/m
linear density of the string = 4.46 × 10⁻⁴ kg/m
Answer:
e. all of these
Explanation:
The fatigue strength is improved by then high alloy steels , high yield steels , high hardened steel , high ultimate steel .
Due to the formation of the improved materials in alloy steels will increase the fatigue strength . Similarly for a high yield steels and hardened steels these cycles to failure will improve .
Answer:
Increasing its charge
Increasing the field strength
Explanation:
For a charged particle moving in a circular path in a uniform magnetic field, the centripetal force is provided by the magnetic force, so we can write:

where
q is the charge
v is the velocity
B is the magnetic field
m is the mass
r is the radius of the orbit
The period of the motion is

Re-arranging for r

And substituting into the previous equation

Solving for T,

So we see that the period is:
- proportional to the charge and the magnetic field
- inversely proportional to the mass and the square of the speed
So the following will increase the period of the particle's motion:
Increasing its charge
Increasing the field strength