Answer:
The constant torque required to stop the disk is 8.6 N-m in clockwise direction .
Explanation:
Let counterclockwise be positive direction and clockwise be negative direction .
Given
Radius of disk , r = 1.33 m
Mass of disc , m = 70.6 kg
Initial angular velocity , 
Final angular velocity , 
Time taken to stop , t = 2.75 min
Let 
be the angular acceleration
We know
=>
=>
Torque required to stop is given by
where moment of inertia , 
=>
Thus the constant torque required to stop the disk is 8.6 N-m in clockwise direction .
Answer:
• As heat is applied to one end of this material, atoms in the hotter region gain vibràtory energy at a maximum amplitude. They transfer it on to their neighboring atoms and heat is transfered along this material in form of vibràtory energy.
Explanation:
<span>The precautions which should
be taken on board a vessel during a lightning storm are:</span>
<span>(i) </span>All
electrical equipments should be unplugged.
<span>(ii) </span>Keep
yourself away from all metal parts such as engines, metal tanks, stoves etc.
<span>(iii) </span><span>Stay inside the boat. </span>
Answer:
B = 1.353 x 10⁻³ T
Explanation:
The Magnetic field within a toroid is given by
B = μ₀ NI/2πr, where N is the number of turns of the wire, μ₀ is the permeability of free space, I is the current in each turn and r is the distance at which the magnetic field is to be determined from the center of the toroid.
To find r we need to add the inner radius and outer radius and divide the value by 2. Hence,
r = (a + b)/2, where a is the inner radius and b is the outer radius which can be found by adding the length of a square section to the inner radius.
b = 25.1 + 3 = 28.1 cm
a = 25.1 cm
r = (25.1 + 28.1)/2 = 26.6 cm = 0.266m
B = 4π x 10⁻⁷ x 600 x 3/2π x 0.266
B = 1.353 x 10⁻³ T
The strength of the magnetic field at the center of the square cross section is 1.3 x 10⁻³ T
Answer: 60mph
Explanation:
Given the following :
First leg travel:
Distance = 30 miles
Time of travel= 30 minutes = 0.5 hour
Second leg travel:
Distance = 60 miles
Time of travel = one hour
Average speed :
Speed = total Distance / time of travel
Total distance in miles = (30 + 60) miles = 90 miles
Total time of travel = 1 hour + 0.5 hour = 1.5 hours
Average speed = total distance traveled / total travel time
Average speed = 90 miles / 1.5 hours
Average speed = 60 miles / hour
= 60mph
