Power is the rate at which work is being done.
Answer:
(a) the deceleration of the player is -80.36 m/s²
(b) the time the collision last is 0.093 s
Explanation:
Given;
Initial velocity of the football player, u = 7.50 m/s
Final velocity of the football player, v = 0
distance traveled = compression of the pad, s = 0.35 m
Part (a) the deceleration of the player
v² = u² + 2as
0 = 7.5² + (2 x 0.35)a
0 = 56.25 + 0.7a
- 56.25 = 0.7a
a = -56.25 / 0.7
a = -80.36 m/s²
Part (b) the time the collision last
v = u + at
t = (v - u)/a
t = (0 - 7.5)/ -80.36
t = - 7.5 / -80.36
t = 0.093 s
<h2>The correct option is (A)</h2>
Explanation:
Travels faster in solids because the particles are closer together.
The reason for the above statement is -
(i) Sound waves travel through the medium (solid, Liquid, and gas), more denser is the medium more is the speed of sound.
(ii) In solid, the particles are arranged very closely and tightly packed therefore the sound waves in solid have the fastest speed or travels fastest in comparison to liquid and gas.
(iii) Slower than solid is the travel of sound waves in liquid than in gas(least dense, particles are far apart.
We will start from the definition of power in terms of the Force. Power could be described as the change of energy in an instant of time. Considering that Energy is the product between the Force and the distance traveled we would arrive at the expression
Here,
F = Force
h = Height
t = Time
As there is no external force, apart from the force of gravity, and this, is constant during the course of the object we will also have to be constant power and therefore this during its course will be the same. The correct answer is (1)
