Answer:
2.47 m
Explanation:
Let's calculate first the time it takes for the ball to cover the horizontal distance that separates the starting point from the crossbar of d = 52 m.
The horizontal velocity of the ball is constant:

and the time taken to cover the horizontal distance d is

So this is the time the ball takes to reach the horizontal position of the crossbar.
The vertical position of the ball at time t is given by

where
is the initial vertical velocity
g = 9.8 m/s^2 is the acceleration of gravity
And substituting t = 2.56 s, we find the vertical position of the ball when it is above the crossbar:

The height of the crossbar is h = 3.05 m, so the ball passes

above the crossbar.
Answer:633.8 KJ
Explanation:
Given
mass of water
Initial temperature
Final temperature 
Specific heat of water
=4190 J/kg-k
heat of vaporization
Heat required for process
=heat to raise water temperature from 20 to 100 +Heat to vapourize water completely
Q=mc
Q=
Q=
Q=
Answer:
Sodium is stored under paraffin oil
Explanation:
Group 1 metals are known to be very highly reactive. The chemical reactivity of the members of the group decreases down the group.
Sodium reacts violently with water and upon exposure to the atmosphere. As a result of this, it must be stored under paraffin oil.
<span><em>Continental drift</em> is one of the earliest ways that geologists thought <em>continents</em><span> moved
over time. It is believed in this theory that the Earth’s movement of the
continents are relative to each other.
This idea was subsumed by the plate tectonics theory. Now, what is the
speed of the continental drift?</span></span>
Continental drift speed is 1x 10^-9 m/s.
This is equivalent to a speed of:
1 x 10 ^-9 m/s
= 1 x 0. 000 000 000 1 m/s
= 0. 000 000 000 1 m/s
Answer:
(a) 1, average velocity = -65.6 m/s
2, average velocity = -64.8 m/s
3, average velocity = -64.16 m/s
(b) The instantaneous velocity is -96 m/s
Explanation:
(a)
Average velocity is given by;

(1)

(2)

(3)

b. y = 235 - 16t²
The instantaneous velocity is given by;
v = dy /dt
dy / dt = -32t
when t = 3 s
v = -32(3)
v = -96 m/s