What is 74000000 in scientific notation

What is the type of intermolecular force in methylated spirits

Olin [163]

. Methylated spirits have ethanol as a base but may include methyl alcohol (methanol) as part of the denaturing process.

7 0

3 years ago

A 1000kg car has a speed of 32m/s. If it takes 7s to stop the car, what is the impulse and the average force acting in the car

Alexus [3.1K]

1) Impulse: -32,000 kg m/s

The impulse acting on the car is equal to the change in momentum of the car:

$I= \Delta p = m (v-u)$

where in this problem we have

m = 1000 kg is the mass of the car

v = 0 m/s is the final velocity of the car

u = 32 m/s is the initial velocity of the car

Substituting values into the equation, we find

$I=(1000 kg)(0-32 m/s)=-32,000 kg m/s$

2) -4751 N

The impulse exerted on the car is also equal to the product between the average force, F, and the duration of the collision, t:

$I=Ft$

where in this situation we know

$I=-32,000 kg m/s$ is the impulse

t = 7 s is the duration of the collision

Solving the formula for F, we find the average force:

$F=\frac{I}{t}=\frac{-32,000 kg m/s}{7 s}=-4,571 N$

and the negative sign means that the force is in the opposite direction to the motion of the car.

5 0

3 years ago

The heating element of a water heater in an apartment building has a maximum power output of 37 kW. Four residents of the buildi

kkurt [141]

Answer:

maximum possible temperature is 34.088°C

Explanation:

Given data

power output Q = 37 kW

volume flow rate = 11 x 10^-5 m3/s

temperature t = 14°C

to find out

maximum possible temperature T

solution

we can say

total water volume = 4 residents × volume flow

total water volume = 4 × 11 x 10^-5 = 44 × 10^-5 m³/s

so we say total water mass = 1000 × volume

total water mass = 1000 kg/m³ × 44 × 10^-5

total water mass = 0.44 kg

we know

dQ/dt = (dm/dt)× (S)× ( T - t)

so here we know specific heat of water S = 4.186 joule/gram °C

37 = 0.44 × 4.186 × (T-14)

T = 34.088°C

maximum possible temperature is 34.088°C

3 0

3 years ago

A fillet weld has a cross-sectional area of 25.0 mm2and is 300 mm long. (a) What quantity of heat (in joules) is required to acc

HACTEHA [7]

Answer:

77362.56 J

163730.28571 J

Explanation:

A = Area = 25 mm²

l = Length = 300 mm

K = Constant = $3.33\times 10^{-6}$

$\eta$ = Heat transfer factor = 0.75

$f_m$ = Melting factor = 0.63

T = Melting point of low carbon steel = 1760 K

Volume of the fillet would be

$V=Al\\\Rightarrow V=25\times 300\\\Rightarrow V=7500\ mm^3=7500\times 10^{-9}\ m^3$

The unit energy for melting is given by

$U_m=KT^2\\\Rightarrow U_m=3.33\times 10^{-6}\times 1760^2\\\Rightarrow U_m=10.315008\ J/mm^3$

Heat would be

$Q=U_mV\\\Rightarrow Q=10.315008\times 7500\\\Rightarrow Q=77362.56\ J$

Heat required to weld is 77362.56 J

Amount of heat generation is given by

$Q_g=\dfrac{Q}{\eta f_m}\\\Rightarrow Q_g=\dfrac{77362.56}{0.75\times 0.63}\\\Rightarrow Q_g=163730.28571\ J$

The heat generated at the welding source is 163730.28571 J

7 0

4 years ago

Difference between weightlessness in space and weightlessness in earth

zubka84 [21]

In space we feel weightlessness because the earth's gravity has less effect on us. The Earth's gravitational attraction at those altitudes is only about 11% less than it is at the Earth's surface. If you had a ladder that could reach as high as the shuttle's orbit, your weight would be 11% less at the top.

5 0

4 years ago