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
WITCHER [35]
4 years ago
11

A car is moving down a flat, horizontal highway at a constant speed of 21 m/s when suddenly a rock dropped from rest straight do

wn from a bridge crashes through the windshield. The rock strikes the windshield at a right angle, and the windshield makes a 60 degree angle with the horizontal.
a. Find the speed of the rock relative to the car when it hits the windshield.
b. Find the distance above the point of contact with the windshield from which the rock was dropped.
c. If the driver had seen what was about to happen just as the rock was being released, how much time would she have had to react before the rock strikes the windshield?
Physics
1 answer:
Naddik [55]4 years ago
7 0

Answer:

a)9.8

Explanation:

because any object falling from any height is 9.8

(sorry that's the only one i know)

You might be interested in
The linear expansivity of a metal p Is twice that of metal q. When these metals are heated through the same temperature, their i
Sidana [21]

Answer:0-------0

do we have options?

Explanation:

4 0
3 years ago
Liquids with convex meniscus​
kobusy [5.1K]

Mercury in a glass tube.

7 0
3 years ago
I need help with this problem on science 8th grade here is the picture of the assignment place help me
Leni [432]

Answer:

the first one is D

Explanation:

so if the others u put are right the the second would be c

7 0
3 years ago
Read 2 more answers
2. What is the total effect of sound produced in an enclosed space called?
Igoryamba
I believe it is Acoustics, the real name for it would be like Reverberation. But go with Acoustics. :)
6 0
3 years ago
If 27 J of work are needed to stretch a spring from 15 cm to 21 cm and 45 J are needed to stretch it from 21 cm to 27 cm, what i
kupik [55]

Answer:

9 cm.

Explanation:

The energy used for stretch the spring from 15 cm to 21 cm will be , E_{1}=27J

The energy used for stretch the spring from 21 cm to 27 cm will be , E_{2}=45J

using the energy of spring formula ,we find that

27 = \frac{1}{2}K((21-L^{2})-(15-L^{2}))

45 = \frac{1}{2}K((27-L^{2})-(21-L^{2}))

Dividing both the equation will get,

\frac{3}{5}=\frac{(21-L)^{2}-(15-L)^{2}}{(27-L)^{2}-(21-L)^{2}}\\5((21-L)^{2}-(15-L)^{2})=3((27-L)^{2}-(21-L)^{2})\\3(729 - 54L + L^{2}- 441 + 42L - L^{2} ) = 5(441 - 42L + L^{2} - 225 + 30L - L^{2} )\\3(288 - 12L) = 5(216 - 12L)\\24L = 216\\L = 9 cm

Therefore, the natural length of the spring is, 9 cm.

4 0
3 years ago
Other questions:
  • you paddle a canoe with the force of 200N. you and the canoe have a combined mass of 97KG . what is the acceleration of the cano
    7·1 answer
  • What do all heterotrophs have in common?
    13·1 answer
  • 1. when estimating the area covered by an object, what type of errors might you make and what are the sources that might have ca
    12·1 answer
  • A car is traveling at a velocity of 7.5 m/s. How far will it get in 34 sec
    10·1 answer
  • If the intensity of an electromagnetic wave is 80 MW/m2, what is the amplitude of the magnetic field of this wave
    14·1 answer
  • Help me answer this please!
    12·1 answer
  • What is photosynthesis ​
    15·2 answers
  • ) The rate of submergence is the total change in the elevation of the pier (two m) divided by the total amount of time involved
    15·1 answer
  • 3. One cubic metre is equal to​
    12·1 answer
  • in fig. 15.12, two identical springs of spring constant 7580 n/m are attached to a block of mass 0.245 kg. what is the frequency
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!