There are different types of contact forces like normal Force, spring force, applied force and tension force.
Answer:b
Explanation: If you look at the line on the graph, you can see that it is going downward, meaning it has a negative slope, and choice b is the only one that has a negative slope
Answer:
(d) III only
Explanation:
We have to observe the motion of the bag with respect to taxi , considering taxi as stationary or inertial frame . Since bag is not moving with respect to taxi , the inertial frame that means , net force on it is zero .So option i and ii are ruled out .
Now how to explain motion of the bag ie why it is stationary ie what are the balancing force acting on it. We know that on a body on circular path , a force called centripetal force is acting on it . So that force must be acting on it . The balancing force is the frictional force which is keeping it stationary with respect to taxi . Hence the third option is correct.
Answer:

Explanation:
Given that,
The elevator is moving up and slowing down at the rate of, 
The acceleration due to gravity, 
Mass of the person, m = 93.3 kg
To find,
The reading of the scale.
Solution,
As the elevator is moving down with some acceleration. The net force acting on it is given by :




So, the scale will read 1194.24 N.
Answer:
The minimum thickness of the Lucite plate is 0.670 μm.
Explanation:
Given that,
Wavelength = 650.0 nm
Index of refraction = 1.485
We need to calculate the minimum thickness of the Lucite plate
Using formula of thickness


Where, n = Index of refraction
= wavelength
Put the value into the formula


Hence, The minimum thickness of the Lucite plate is 0.670 μm.