If the average speed of a car is 45 km/hr, how far can it travel in 40 minutes?

Find the mass of a sample that has a dersity of 2 g/mL and a volume of 10 mL

In-s [12.5K]

Answer:

mass = volume x density.

Explanation:

2 x 10 = 20g

4 0

3 years ago

A person travels by car from one city to another. She drives for 23.5 min at 74.5 km/h, 15.9 min at 111 km/h, 49.2 min at 38.7 k

Drupady [299]

The product of speed and time is distance. To calculate the total distance you multiple the speed in kilometers per second by the time at that speed in seconds, do this for all 3 different speeds then add them up, the 17.4 minutes eating does not affect the answer at all. to convert from minutes to seconds multiply time in minutes by 60, to convert from km/h to km/s divide km/h by 3600.

(23.5x60)x(74.5/3600) = 29.2km (rounded to 1 decimal place)
+
(15.9x60)x(111/3600) = 29.4km (rounded to 1 decimal place)
+
(49.2x60)x(38.7/3600) = 31.7km
=90.3km

The brackets are not necessary but i think it makes it more clear what is happening in your working.

3 0

3 years ago

How long must a flute be in order to have a fundamental frequency of 262 Hz (this frequency corresponds to middle C on the evenl

spin [16.1K]

Answer:

L=0.654 m

Explanation:

Concepts and Principles

1- The speed of sound in air is expressed as a function of the temperature of air as follows:

v=(331 m/s)√(1+T_C/273°C) (1)

where 331 m/s is the speed of sound in air at temperature 0°C and Tc is the temperature of air in Celsius.

Standing Wave Patterns in Pipes:

A pipe open at both ends can have standing wave patterns with resonant frequencies:

f=v/λ=nv/2L n=1,2,3.........

where v is the speed of sound in air.

Given Data

f_1 (fundamental frequency of the flute) = 262 Hz

T (temperature of the air) = 20°C

The flute is open at both ends.

Required Data

We are asked to determine the length of the tube.

Solution

The speed of sound in air at temperature T = 20°C is found from Equation (1):

v=(331 m/s)√(1+T_C/273°C)

=342.91 m/s

The fundamental frequency of the flute is found by substituting n = 1 into Equation (2):

f=v/2L

Solve for L:

L=v/2f_1

L=0.654 m

7 0

3 years ago

If the kinetic energy of the 40kg box is 784 J, what is the velocity before it strikes the ground?

mamaluj [8]

Answer:

Explanation:

$KE=\frac{1}{2}mv^2$

$784=\frac{1}{2}(40)v^2$

$784=20v^2$

$39.2=v^2$

$v=6.26m/s$

4 0

3 years ago

Definition of distance in physics

solniwko [45]

Answer:

Distance is a scalar quantity that refers to "how much ground an object has covered" during its motion. Displacement is a vector quantity that refers to "how far out of place an object is"; it is the object's overall change in position.

Explanation:

8 0

3 years ago