ANSWER

EXPLANATION
Parameters given:
Mass of car, mc = 1103 kg
Mass of truck, mt = 4919 kg
Initial velocity of car, uc = 18 m/s
Inital velocity of truck = 0 m/s
To solve this problem, we have to apply the law of conservation of momentum, which states that the total momentum of a system is constant.
This implies that:

Since the car and the truck stick together after the collision, they will have the same final velocity.
Hence:

Substitute the given values and solve for v (final velocity):

That is the final velocity of the two-vehicle mass.
Answer:
20.45%
Explanation:
The probability that the student got a B is

Now, how many students are there in total?
The answer is

How many students got a B?
The answer is

therefore, the probability that the student has got a B is

Hence, the probability that a student has got a B is 20.45%
The radio waves are electromagnetic wave, so it travels with velocity of light i.e
.
We can use the relation between frequency, wavelength and speed as

Here c is speed of light,
is wavelength and f is frequency and its value is given 99.90 FM, it is actually in megahertz (i.e 99.90 MHz).
Therefore,
.
Thus, the broadcast wavelength of the given radio station is 3.003 m.
Answer:
C
Explanation:
According to Newton's first law of motion, which states that a body will continue in its state of rest or uniform motion unless acted upon by an external force to change its state of rest or uniform motion. So, the Voyagers spacecraft will continue to move in the same way at the constant speed of 50,000 mph unless acted upon by a force.
The maximum pressure variations the human ear can withstand above and below atmospheric pressure is around 30 pa. the normal atmospheric pressure is around 101325 pa. hence the variation in the maximum pressure for human ear is very small as compared to the atmospheric pressure. if the ear is exposed to a pressure greater than this , it can cause permanent damage to the ear.