Let us examine the given situations one at a time.
Case a. A 200-pound barbell is held over your head.
The barbell is in static equilibrium because it is not moving.
Answer: STATIC EQUILIBRIUM
Case b. A girder is being lifted at a constant speed by a crane.
The girder is moving, but not accelerating. It is in dynamic equilibrium.
Answer: DYNAMIC EQUILIBRIUM
Case c: A jet plane has reached its cruising speed at an altitude.
The plane is moving at cruising speed, but not accelerating. It is in dynamic equilibrium.
Answer: DYNAMIC EQUILIBRIUM
Case d: A box in the back of a truck doesn't slide as the truck stops.
The box does not slide because the frictional force between the box and the floor of the truck balances out the inertial force. The box is in static equilibrium.
Answer: STATIC EQUILIBRIUM
Answer;
=32.15 meters
Explanation;
Use the formula
s= ut+ 0.5 a (t)^2 to find out 's'
where s= distance traveled
u=initial velocity which is zero in this case
t= time taken to travel 's' distance
a=acceleration (due to gravity on moon i.e 1.62 m/s^2 )
Therefore;
S = 0.5 * 1.62 * 6.3 * 6.3
= 32.1489 meters
Thus; the crater is 32.15 meters deep.
Planck's constant. A physical constant adopted in 2011 by the CGPM.
Answer:0.43
Explanation:
Given
mass of car 
Speed of car 
Distance traveled before coming to halt 
Let
the coefficient of friction
Maximum deceleration road can provide during motion is

using 



Answer:
option (c)
Explanation:
When an object thrown upwards, the value of acceleration acting on the object is acceleration due to gravity which is always acting towards the earth.
As it falls downwards, the acceleration is again equal to the acceleration due to gravity.
So, the ball's acceleration is constant.