Option (A ) is correct.
Explanation:
susan is moving with constant velocity, so both the direction and magnitude of the velocity remains same. so the acceleration of susan =0. This is because an object gets accelerated when either the magnitude or direction of the speed changes.
now the force is given by

F= force
m= mass
a= acceleration
Here a =0
so F= 0
so the net force on susan is zero.
If the lightbulb A in the circuit shown in the image burned out, the path for the current to flow is disrupted because one of its terminals is connected direct to the source. So, there will be no current through the lightbulbs B, C, and D, and they will turn off. Similarly it will happen, if the lightbulb D burned out.
If the lightbulb B burned out the current will continue circulating through the lightbulbs A, C, and D, because lightbulb B is connected in parallel. Similarly it will happen, if the lightbulb C burned out.
Answer:
Describing a Force:
To fully describe the force acting upon an object, you must describe both its magnitude and direction. Thus, 10 Newtons of force is not a complete description of the force acting on an object. 10 Newtons, downwards is a complete description of the force acting upon an object.
Explanation:
Answer: 1.12 m
Explanation:
This situation is related to parabolic motion, hence we can use the following equations:
(1)
(2)
Where:
is the ball final height (when it hits the ground)
is the ball initial height
is the initial velocity
is the angle at which the ball was launched
is the time
is the acceleration due gravity
is the horizontal distance the ball travels
Rewriting (1) with the given values:
(3)
Multiplying all the eqquation by -1 and rearranging:
(4)
So, since we have a quadratic equation here (in the form of
, we will use the quadratic formula to find
:
(5)
Where
,
,
Substituting the known values and choosing the positive result of the equation, we have:
(6)
Now, substituting (6) in (2):
(7)
(8) This is the horizontal distance at which the ball hits the ground.
The activation energy is 10 kJ and the reaction is exothermic.