Saying english so we can help u
For vertical motion, use the following kinematics equation:
H(t) = X + Vt + 0.5At²
H(t) is the height of the ball at any point in time t for t ≥ 0s
X is the initial height
V is the initial vertical velocity
A is the constant vertical acceleration
Given values:
X = 1.4m
V = 0m/s (starting from free fall)
A = -9.81m/s² (downward acceleration due to gravity near the earth's surface)
Plug in these values to get H(t):
H(t) = 1.4 + 0t - 4.905t²
H(t) = 1.4 - 4.905t²
We want to calculate when the ball hits the ground, i.e. find a time t when H(t) = 0m, so let us substitute H(t) = 0 into the equation and solve for t:
1.4 - 4.905t² = 0
4.905t² = 1.4
t² = 0.2854
t = ±0.5342s
Reject t = -0.5342s because this doesn't make sense within the context of the problem (we only let t ≥ 0s for the ball's motion H(t))
t = 0.53s
The correct matching are the following:
- A. magnetic field: prevents charged particles from the sun from reaching the surface
- B. ozone: filters cancer-causing rays from the sun
- C. carbon dioxide: retains heat energy from the sun in the atmosphere
- D. water in oceans, lakes, rivers and streams: moderates changes in temperature on the surface
The electromagnetic field of the Earth protects us from solar wind by deflecting it. Without it, the charged particles would strip away our ozone, which will lead to the end of life on Earth.
The ozone is a layer in the stratosphere that filters the suns rays. It filters the UV rays by absorbing it. This prevents the UV rays from damaging the surface of the Earth.
Carbon dioxide retains heat in the atmosphere, which creates a greenhouse effect. It is beneficial for us, but because human activity like industrial activities emit so much carbon in the atmosphere that it ends up being harmful.
Bodies of water found on Earth regulate the temperature of the Earth through ocean currents. It brings in both cold and warm air to land which also affect precipitation.
Long explanation, I know, but maybe this will help you out in the long run. Good Luck!
Answer:
a. V=11.84 m/s
b.x=0.052m
Explanation:
a).
Given
,
, 
.
b).
No friction on the ball so:
Answer:
B. equals zero
Explanation:
Given data
one complete cycle = heat flow
solution
we have given that when heat engine complete 1 cycle change in energy = net heat flow
that is always equal to zero
from first law of thermodynamics that
ΔU = Q + W
we know ΔU is the change internal energy in system and Q is net heat transfer in system and W is net work done in system
therefore change of internal energy during one cycle
ΔU = Ufinal - Uinitial
ΔU = Uinitial - Uinitial = 0
