Answer:
If there are no forces acting upon the object, then there is no acceleration. If there is no acceleration, then the object will move with a constant velocity.
Explanation:
Medium.
Medium is matter, and electromagnetic waves do not need matter to travel. Just like the sun, its plasma light travels across space to reach us.
We need to use the kinematic equation
S=ut+(1/2)at^2
where
S=displacement (+=up, in metres)
u=initial velocity (m/s)
t=time (seconds)
a=acceleration (+=up, in m/s^2)
Substitute values
S=displacement = 1.96-2.27 = -0.31 m (so that shot does not hit his head)
u=11.1
a=-9.81 (acceleration due to gravity)
-0.31=11.1t+(1/2)(-9.81)t^2
Rearrange and solve for t
-4.905t^2+11.1t-0.31=0
t=-0.02756 or t=2.291 seconds
Reject the negative root to give
t=2.29 seconds (to 3 significant figures)
Answer:
The velocity of the skateboard is 0.774 m/s.
Explanation:
Given that,
The spring constant of the spring, k = 3086 N/m
The spring is stretched 18 cm or 0.18 m
Mass of the student, m = 100 kg
Potential energy of the spring, 
To find,
The velocity of the car.
Solution,
It is a case of conservation of energy. The total energy of the system remains conserved. So,
v = 0.774 m/s
So, the velocity of the skateboard is 0.774 m/s.
This question is incomplete because the options are missing; here is the complete question
The ozone layer is found in which layer of the atmosphere?
A. Stratosphere
B. Mesosphere
C. Thermosphere
D. Troposphere
The correct answer is A. Stratosphere
Explanation:
The ozone layer as indicated by its name is mainly composed of Ozone (O2), this layer is essential for life because it filters ultraviolet radiation and acts as a greenhouse effect gas by trapping part of the heat from the sun. Additionally, the ozone layer is located in the stratosphere, which is the second layer of the atmosphere and can be found between 20 km to 50 km from Earth's surface. Moreover, the existence of the ozone layer in the stratosphere makes the temperature increase with height due to the radiation of the sun filter by ozone.
