1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
olganol [36]
3 years ago
6

Select the correct answer.

Physics
2 answers:
FinnZ [79.3K]3 years ago
8 0
2 hours is the answer because you do 45x2=90
Bumek [7]3 years ago
3 0

Answer:

B. 2 Hours

Explanation:

If you are going 45 miles per hour, you will travel 45 miles in 1 hour. It will take you 2 hours to travel 90 miles at a speed of 45 miles per hour.

You might be interested in
This diagram shows the forces acting on a car. The center dot represents the car, a the arrows represent the forces acting on th
mylen [45]
Need diagram right? Post it
5 0
3 years ago
Approximately how many atoms are there along a 9.5 cm line
uranmaximum [27]
First convert 5.5 cm to meters.

(5.5 cm / 1) x (m / 100 cm) = 0.055 m

A typical atom is about 1.0E-10 m in diameter; thus:

0.055 m / 1.0E-10 m = 5.5E8 atoms or 550,000,000 end-to-end atoms in 5.5 cm
4 0
3 years ago
1) A boy drags a wooden crate with a mass of 20 kg, a distance of 12 m, across a rough level floor at a constant speed of 1.5 m/
mojhsa [17]

Answer: a) 49.560 and 21.13 b) i) 50 N, ii) 196 N iii) 196 N iv) 47.685 N

c) i) 594.72 ii) 0 iii) 0 iv) 0

d) 594.72

Explanation: question a)

The force is inclined at an angle of 25° to the horizontal

The horizontal component of force = 50 cos 25° = 49.560 N

The vertical component of force = 50 sin 30°= 21.130N

Question b)

i) according to the question applied force is 50 N

ii) if g = 9.8m/s², w=mg where m = mass of object = 20kg hence weight = 20* 9.8 = 196 N

iii) the normal force is the force the floor exerts on the body as a result of the weight of the object.

Normal reaction R = W = mg, we already deduced that w = mg, hence R = 196 N.

iv) according to newton's laws of motion

F - Fr = ma

F = applied force = horizontal component of force = 49.560 N.

We need to get the acceleration (a) by using Newton laws of motion before we can be able to compute the frictional force..

The body started from rest hence initial velocity u = 0

Final velocity v = 1.5m/s distance covered (s) = 12m

v ² = u² + 2as

But u = 0

v² = 2as

1.5² = 2(a) * 12

2.25 = 24a

a = 2.25/24 = 0.09735m/s²

From F - Fr = ma

49.560 - Fr = 20 * 0.09735

49.560 - Fr = 1.875

Fr = 49.560 - 1.875

Fr = 47.685 N

Question c)

i) The applied force = 49.560 N, distance covered = 12m

Work done = force * distance

Work done = 49.560 * 12

Work done = 594.72 J

ii) the weight of the object does not make the object move a distance, hence work done = 0 ( since distance covered is 0)

iii) the normal force is the same thing as the weight and they did not cover any distance hence work done is zero.

iv) the frictional force does not cover any distance, hence work done is zero.

Question d)

The total work done = work done by applied force + work done by weight + work done by normal reaction + work done by frictional force.

Total work done = 594.72 + 0 + 0 + 0 = 594.72 J

8 0
3 years ago
Please help! Will mark best answer!!
MA_775_DIABLO [31]
The answer is (A) hope it helps 
7 0
3 years ago
Read 2 more answers
Cori uses 475 J of energy from her muscles to push a bar 1 m on a weight machine at the gym. Between the bar’s motion , the heat
dimulka [17.4K]

Answer:

475

Explanation:

Cori does not exert any more force than 475 J, so 475 is the answer.

5 0
3 years ago
Read 2 more answers
Other questions:
  • In the presence of a nucleus the energy of a y-ray photon can be converted into an electron-positron pair. Calculate the minimum
    8·1 answer
  • Edwin Hubble was one of the first scientists to show that galaxies are getter farther apart from each other. (A.) True (B.) Fals
    10·2 answers
  • Which pair of countries are both part of the crib Caribbean cultural regions in North America
    12·1 answer
  • This i relatively easy but still, i attached a picture
    5·1 answer
  • A rectangular metal block measures 10cm x4 cm x 5cm. Given that the density of the
    9·1 answer
  • What will happen when these two waves interact?
    9·1 answer
  • A delivery truck driver's round-trip route from the warehouse takes her 5 km east, then 2 km north, then 5 km west, and then 2 k
    9·1 answer
  • A mass m on a spring with a spring constant k is in simple harmonic motion with a period T. If the same mass is hung from a spri
    9·1 answer
  • When air mass is caught between two cold fronts the result is a _______ front.
    6·1 answer
  • Calculate the volume that 42g of nitrogen gas (N2)occupies at standard temperature and pressure.​
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!