Answer:
-48 N
Explanation:
mass of door (m) = 4 kg
acceleration of the door = 12 m/s^{2}
force exerted by the person = 48 N
From Newton's third law of motion, action and reaction are equal but opposite. Therefore the force exerted on the door by the person which is 48 N will be the same as the force exerted on the person by the door but opposite in its direction, and this would be - 48 N
Answer: The energy absorbed by the reaction from the water is 996 Joules.
Explanation:
Energy absorbed by the reaction or energy lost by the water to the reaction,Q.
Mass of the the reaction ,m = 60 g
Specific heat of water = c = 4.15 J\g ^oC
Change is temperature=

Negative sigh indicates that energy was given by the water to the reaction.
The energy absorbed by the reaction from the water is 996 Joules.
Answer:
The fundamental frequency of can is 2.7 kHz.
Explanation:
Given that,
A typical length for the auditory canal in an adult is about 3.1 cm, l = 3.1 cm
The speed of sound is, v = 336 m/s
We need to find the fundamental frequency of the canal. For a tube open at only one end, the fundamental frequency is given by :

So, the fundamental frequency of can is 2.7 kHz. Hence, this is the required solution.
Car X traveled 3d distance in t time. Car Y traveled 2d distance in t time. Therefore, the speed of car X, is 3d/t, the speed of car Y, is 2d/t. Since speed is the distance taken in a given time.
In figure-2, they are at the same place, we are asked to find car Y's position when car X is at line-A. We can calculate the time car X needs to travel to there. Let's say that car X reaches line-A in t' time.

Okay, it takes t time for car X to reach line-A. Let's see how far does car Y goes.

We found that car Y travels 2d distance. So, when car X reaches line-A, car Y is just a d distance behind car X.
Answer:
Explanation:
A unit used to measure a vector quantity is the
c) Newton