Photovoltaic cells: a) have become more economical to produce and use over the past 25 years. b) are the most efficient means of
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Answer:
The minimum speed must the car must be 13.13 m/s.
Explanation:
The radius of the loop is 17.6 m. We need to find the minimum speed must the car traverse the loop so that the rider does not fall out while upside down at the top.
We know that, mg be the weight of car and rider, which is equal to the centripetal force.
So, the minimum speed must the car must be 13.13 m/s.
Answer:
static coefficient = 0,203 & kinetic coefficient = 0,14
Explanation:
There are two (2) conditions, when the desk is about to move and when the desk is moving. In the attachements you can see the two free body diagram for each condition.
In the first condition, there is no movement and the force is 12 N, in the image we can see the total forces are equal to 0 and by the definition of the friction force we can get the static friction coefficient.
In the second condition there is movement in the direction of the force which is equal to 8 N, again by the definition of the friction force we can get the kinetic friction coefficient. Since the desk is moving with constant velocity there is not acceleration.
Answer:
part (a)
Part (b)
Explanation:
Given,
- mass of the smaller disk =
- Radius of the smaller disk =
- mass of the larger disk =
- Radius of the larger disk =
- mass of the hanging block = m = 1.60 kg
Let I be the moment of inertia of the both disk after the welding,
part (a)
A block of mass m is hanging on the smaller disk,
From the f.b.d. of the block,
Let 'a' be the acceleration of the block and 'T' be the tension in the string.
Net torque on the smaller disk,
From eqn (1) and (2), we get,
part (b)
In this case the mass is rapped on the larger disk,
From the above expression of the acceleration of the block, acceleration is only depended on the radius of the rotating disk,
Let '' be the acceleration of the block in the second case,
From the above expression,
Answer:1200 kg
Explanation:
Given
Electromagnet can lift a mass of
Magnetic force necessary to hold mass is proportional to Magnetic field
and magnetic field (B) is proportional to NIA
where N=no of turns
I=current in the magnet
A=area of cross-section
When we double the no of turns and triple the current then
N becomes 2 N
I becomes 3 I
therefore magnetic field becomes 6 times
Thus magnetic force becomes 6 times and we can say that electromagnet can hold the 6 times of given weight
i.e.