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3 years ago

A drag racer starts from rest and accelerates at 7.4 m/s2. How far will he travel in 2.0 seconds?

1 answer:

4 0

Using the kinematic equation below we can determine the distance traveled if t=2, a=7.4m/s^2. First we must determine the final velocity:

$v_{final}=v_{initial}+\frac{1}{2}at\\\\v_{final}=0+(7.4m/s^2)(2s)=34.8m/s$

Now we will determine the distance traveled:

$v_{final}^2=v_{initial}^2+2a \Delta x\\\\\Delta x = \frac{v_{final}^2}{2a} =\frac{(34.8)^2}{(2)(7.4)}=81.83 m$

Therefore, the drag racer traveled 81.83 meters in 2 seconds.

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(7) A 2500 lbm car moving at 25 mi/hr is accelerated at a constant rate of 15 ft/s2 up to a speed of 50 mi/hr. What is the force

balandron [24]

Answer:

The force is $F = 1164.6\ lbf$

The time is $\Delta t = 2.44 \ s$

Explanation:

From the question we are told that

The mass of the car is $m = 2500 \ lbm$

The initial velocity of the car is $u = 25 \ mi/hr$

The final velocity of the car is $v = 50 \ mi/hr$

The acceleration is $a = 15 ft/s^2 = \frac{15 * 3600^2}{ 5280} = 36818.2 \ mi/h^2$

Generally the acceleration is mathematically represented as

$a = \frac{v-u}{\Delta t}$

=> $36818.2 = \frac{50 - 25 }{ \Delta t}$

=> $t = 0.000679 \ hr$

converting to seconds

$\Delta t = 0.0000679 * 3600$

=> $\Delta t = 2.44 \ s$

Generally the force is mathematically represented as

$F = m * a$

=> $F = 2500 * 15$

=> $F = 37500 \ \frac{lbm * ft}{s^2}$

Now converting to foot-pound-second we have

$F = \frac{37500}{32.2}$

=> $F = 1164.6\ lbf$

7 0

3 years ago

Fill in the blanks below: Urgently need help!!!

miskamm [114]

Answer:

In a circuit , VOLTAGE can be said to be the "source" or the "push of electrons". This push then creates what is known as a  CURRENT , which is the flow of electric charge through the circuit. This flow can the slowed down or restricted by RESISTOR , and this is also what can be harnessed in order to use electric ENERGY .

Explanation:

Voltage:

It is the 'push' that causes charges to move in a wire or other electrical conductor, also it is a Source input to the electric circuit.

Measured in Volts.

Current:

An electric current is the rate of flow of electric charge from a point or through a region.

Measured in Ampere.

Resistor:

Resistor is used to resist the flow of charge or to resist the current called as Resistance.

Measured in Ohms.

Electric Energy:

Electrical energy is a form of energy resulting from the flow of electric charge.

Measured in Joules.

In a circuit , voltage can be said to be the "source" or the "push of electrons". This push then creates what is known as a current, which is the flow of electric charge through the circuit. This flow can the slowed down or restricted by resistor, and this is also what can be harnessed in order to use electric energy.

8 0

3 years ago

A body starting from rest and moves with uniform acceleration. The velocities of the body are 40 m/s at the 4th second and 60 m/

Sergeeva-Olga [200]

Answer:

GIVEN

u is 40m/s and v=60m/s

time is 4s

therefore acceleration =60-40/4

=20/4=5m/s^2

b)next 2 sec=70m/s

8 0

3 years ago

To heat the house, the boiler transfers 15 MJ of energy in 10 minutes.

Harrizon [31]

The formula is P = E/t, where P means power in watts, E means energy j , and t means time in seconds. This formula states that power is the consumption of energy per unit of time.

P = 15 M / 10*60

M = mega = 10⁶

15 *10⁶ / 600

= 25000 watt

8 0

2 years ago

Use these relationships to determine the number of calories to change 1.5 kg of 0∘c ice water to 1.5 kg of 100∘c boiling water.

aivan3 [116]

The latent heat of fusion of water is 80 cal/g.
The specific heat of water is 1 cal/g-C.
The latent heat of vaporization of water is 540 cal/g.
Therefore, if we have 1.5 kg = 1500 g, the total heat requirement is:
1500 g[(80 cal/g) + (1 cal/g-C)(100 - 0)C + (540 cal/g)] = 1500 g(720 cal/g) = 1,080,000 cal.

4 0

3 years ago