During a race, a runner runs at a speed of 6 m/s. 2 seconds later, she is running at a speed of 10 m/s. What is the runner’s acceleration? Show your work.

Answer:

Explanation:

Expression for relative velocity

=

= (.54 + .82 )c/

= 1.36 c / 1.4428

= .94 c

β = .94

Answer:

The answer is 96ft^3

Explanation:

T=initial concrete mixture

S1=initial amount of sand

S2=final amount of sand

T2=final amount concrete mixture

C=amount of cement

Data:

T=480Ft^3

 the quantities of the initial mixture are

S=0.7*480=336Ft^3

C=0.3*480=144 Ft^3

 we pose the following equations

144+S2=T2

T2*0.75=S2  

if we solve

S2=144/(1/0.75-1)=432ft^3

to know how much we should add we subtract it from the initial amount of sand

Answer=432ft^3-336ft^3=96ft^3

Explanation :

The direction of current flow is in opposite direction to that of the direction of electron flow.

Electric current is defined as the electric charge per unit time. Simply it is the flow of electrons in a circuit. When an electric potential is applied in a circuit, the current moves from the positive terminal of a battery to the negative terminal.

But the electrons travel from negative to the positive terminal i.e in the direction opposite to that of current flow.

Answer:

a. 5 seconds

b. 5 seconds

c. 0.2 Hz

Explanation:

a) For 2 complete cycles, time taken is 10 s.

Thus, for 1 complete cycle, the pendulum would take = 10 s÷ 2 = 5 s

b) The time period of a pendulum can be defined as time to complete 1 cycle/oscillation. This is calculated in part a. Thus, time period of the pendulum is 5 s.

c) The frequency of a pendulum can be define number of cycles/oscillations in 1 s. It takes 5 s to complete 1 cycle.

In 1 s, number of cycles = (1 ÷ 5) s⁻¹ = 0.2 Hz.