Answer:
The frequency of wave is 4 hertz.
Explanation:
Given,
wave length = 8m
speed of sound ( v) = 32 m/s
frequency ( f) = ?
we know,
v = f × lambda
or, 32 = f × 8
or, f = 32/8
or, f = 4 Hertz.
The correct answer is the Type of batteries
Explanation:
In an experiment, it is normal the researcher modifies one variable, in this case, the number of batteries (independent variable), and this variable affects the variable tested, in this case, the brightness of the bulb (dependent variable).
However, other factors or variables should be constant to guarantee the results are reliable. In this context, one factor that the student should keep constant is the type of batteries he uses because this is not one of the main variables and therefore it is not expected he changes this on purpose or this is affected by other variables. Moreover, by making any change the experiment can be negatively affected. For example, batteries might differ in their power capacity this can affect the brightness of the bulbs.
Answer:
Unbalanced forces
Explanation:
Unbalanced forces acting on an object can change the object's speed, causing it to speed up or slow down.
I think the answer is constant
Answer:
a) 
b) 
c) 
d) 
Explanation:
Given:
mass of the player, 
mass of the ball, 
initial velocity of the player, 
initial velocity of the ball, 
a)
<u>Case:</u> When the player and the ball are moving in the same direction.
where:
total mass after the player catches the ball
v = final velocity of the system
b)
Initial kinetic energy of the system:
![KE_i=\frac{1}{2} [m_p.v_p^2+m_b.v_b^2]](https://tex.z-dn.net/?f=KE_i%3D%5Cfrac%7B1%7D%7B2%7D%20%5Bm_p.v_p%5E2%2Bm_b.v_b%5E2%5D)
![KE_i=\frac{1}{2} [102.5\times 8.5^2+0.47\times 22.5^2]](https://tex.z-dn.net/?f=KE_i%3D%5Cfrac%7B1%7D%7B2%7D%20%5B102.5%5Ctimes%208.5%5E2%2B0.47%5Ctimes%2022.5%5E2%5D)
Final kinetic energy of the system:
∴Change in kinetic energy
c)
<u>Case:</u> When the player and the ball are moving in the opposite direction.
d)
Final kinetic energy in this case:
∴Change in kinetic energy:
