An athlete practicing for a track meet ran 400 meter in 50 seconds. What was his average speed?

A firefighter with a weight of 707 N slides down a vertical pole with an acceleration of 2.79 m/s2, directed downward. (a) What

DedPeter [7]

Answer:

The vertical force acting on the firefighter = 908.27 N

Explanation:

Force: Force of a body is defined as the product of mass and its acceleration. The S.I unit of force is Newton (N)

The vertical force acting on the firefighter = Force due to the weight of the firefighter + force due to acceleration.

Ft = Fw - Fa

Where Ft = The vertical force acting on the firefighter, Fw = Force due to the weight of the firefighter, Fa = force due to acceleration.

Fw = mg

Making m the subject of formula in the equation above

m = Fw/g................... Equation 1

Where m = mass of the firefighter, g = acceleration due to gravity,

Given: Fw = 707 N,

Constant: g = 9.8 m/s²

Substituting these values into eqaution 1

m = 707/9.8

m = 72.14 kg.

But, Fa = ma

Where a = acceleration of the firefighter.

Given: a = 2.79 m/s², 

And m = 72.14 kg

Fa = 72.14 × 2.79

Fa = 201.27 N

Therefore, Ft = 707 + 201.27 = 908.27 N

Ft = 908.27 N

The vertical force acting on the firefighter = 908.27 N

7 0

3 years ago

A fire truck has a searchlight with a resistance of 60 (ohm) which is placed across a 24-V battery. What is the current in this

Mariulka [41]

Answer: 0.4 Amps

Explanation:

Voltage of battery = 24 Volts

Current I = ?

Resistance of searchlight (R)= 60ohms (Ω is the symbol for ohms)

Then, apply the formula for ohms law

Voltage = Current x resistance

i.e V = I x R

24V = I x 60Ω

I = 24V / 60Ω

I = 0.4 Amps (Amps is the unit of current)

Thus, the current in the circuit is 0.4 Amps

3 0

3 years ago

7. Two children of mass 20 kg and 30 kg sit balanced on a seesaw with the pivot point located at the center of the seesaw. If th

Ainat [17]

Answer:

Explanation:

Given

mass of children $m_1=20\ kg$

$m_2=30\ kg$

distance between two children $L=3\ m$

suppose small child is at a distance of x m from pivot point

so torque of small child and heavier child must be equal

$20\times (x)=30\times (3-x)$

$2x=9-3x$

$5x=9$

$x=1.8\ m$

7 0

3 years ago

One of the way atoms bond with each other would be through:

Galina-37 [17]

Answer:

ehdgywi

Explanation:

djhcuowhciwurvgwyirgvy mm. ncmsmsmx. n. mssmsmiwvfiywrvvkjbwviverbladcnviwrgqecocqeboodqeugচঠচবি

8 0

3 years ago

A rubber band has potential energy of 5 J. If the spring constant of the rubber band is 50 N/m, what is the displacement of the

Valentin [98]

To determine the displacement, since we are given the potential energy, we use the equation for potential energy. For a spring, it is one-half the product of the spring constant and the square of the displacement. We do as follows:

PE = kx^2/2
5 Nm = 50N/m (x^2)
x = 0.32 m

Therefore, the displacement would be 0.32 m.

7 0

3 years ago

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