Answer:
a) t=1s
y = 10.1m
v=5.2m/s
b) t=1.5s
y =11.475 m
v=0.3m/s
c) t=2s
y =10.4 m
v=-4.6m/s (The minus sign (-) indicates that the ball is already going down)
Explanation:
Conceptual analysis
We apply the free fall formula for position (y) and speed (v) at any time (t).
As gravity opposes movement the sign in the equations is negative.:
y = vi*t - ½ g*t2 Equation 1
v=vit-g*t Equation 2
y: The vertical distance the ball moves at time t
vi: Initial speed
g= acceleration due to gravity
v= Speed the ball moves at time t
Known information
We know the following data:
Vi=15 m / s
t=1s ,1.5s,2s
Development of problem
We replace t in the equations (1) and (2)
a) t=1s
=15-4.9=10.1m
v=15-9.8*1 =15-9.8 =5.2m/s
b) t=1.5s
=22.5-11.025=11.475 m
v=15-9.8*1.5 =15-14.7=0.3m/s
c) t=2s
= 30-19.6=10.4 m
v=15-9.8*2 =15-19.6=-4.6m/s (The minus sign (-) indicates that the ball is already going down)
Answer:
No
Explanation:
Unless there are other external forces, this will never be true. Because according to energy conservation, potential energy will be converted to kinetic energy as the ball falls down (so it loses height and gain speed). And vice versa, kinetic to potential when it bounces back. So the potential energy after must be the same (or smaller if losing heat to external environment), so it can only get the the same height or less, but not more.
Answer:
Hello your question is poorly written hence I will just give the difference between conduction and convection
answer :
Conduction occurs when there is direct contact between solids and source of heat. while convection occurs when there is transfer of thermal energy due to movement of liquid or gas
Explanation:
when a pot of water is placed on a hot stove the pot is heated through conduction because the metal pot is in direct conduct with the heat from the stove ( which is the primary source of heat in this scenerio ).
while the heat transfer from the hot pot to the water is executed through convection this is because heat transfer via convection requires the movement of liquid or gas. as the warmer liquid moves over to the top the cooler liquid goes below inside the pot that way the whole liquid becomes warm .
Using the Planck's Equation, comes:
If you notice any mistake in my english, please let me know, because i am not native.
Answer:
4589.05 year
Explanation:
The relation of activity is given by 
we have given 
Half life 
We know that half life 
So 
